JPH09304320A - Detecting device for degree of pollution - Google Patents
Detecting device for degree of pollutionInfo
- Publication number
- JPH09304320A JPH09304320A JP12286596A JP12286596A JPH09304320A JP H09304320 A JPH09304320 A JP H09304320A JP 12286596 A JP12286596 A JP 12286596A JP 12286596 A JP12286596 A JP 12286596A JP H09304320 A JPH09304320 A JP H09304320A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- degree
- contamination
- waiting time
- terminal voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、空気の汚れ具合を
検出する汚染度合検出装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pollution degree detecting device for detecting the degree of contamination of air.
【０００２】[0002]
【従来の技術】従来より、ＳｎＯ2 、Ｉｎ2 Ｏ3 、ＷＯ
3 等の金属酸化物半導体を使用した半導体式のガスセン
サが知られている。この様な、半導体式のガスセンサ
は、温度や湿度等の環境条件、製造時における素材
の混合比や、素材に混合する触媒の分布のバラつき、
ガスセンサを配置する空間が狭い（密閉空間が狭いとガ
スが壁等に吸着する）、内蔵ヒータの抵抗値のバラツ
キ等の要因により抵抗値自体の変化の影響を受け易い
（図６参照）。従って、図７に示す方法（従来技術１）
や、図８に示す方法（従来技術２）で対応していた。 2. Description of the Related Art Conventionally, SnO 2 , In 2 O 3 , WO
A semiconductor gas sensor using a metal oxide semiconductor such as 3 is known. Such a semiconductor gas sensor, environmental conditions such as temperature and humidity, the mixing ratio of the materials at the time of production, the distribution of the catalyst to be mixed with the materials,
The space in which the gas sensor is arranged is narrow (gas is adsorbed on a wall when the closed space is narrow), and the resistance value itself is susceptible to changes due to factors such as variations in the resistance value of the built-in heater (see FIG. 6). Therefore, the method shown in FIG. 7 (prior art 1)
Alternatively, the method shown in FIG. 8 (prior art 2) is used.
【０００３】（従来技術１）マイクロコンピュータ１０
０の電源電圧は通常５Ｖであるので、マイクロコンピュ
ータ１００が処理可能な入力電圧の上限／下限は、４．
８Ｖ／０．２Ｖである。そこで、ガスセンサ１０１を常
温常湿（温度約２５℃、湿度約６０％）の環境下に置
き、上記、、に起因する変位を解消する為、可変
抵抗器１０２を調整して検知部１０３に印加する電圧を
変化させ、端子電圧Ｖｓを中央値Ｖｓｃ（＋４．８Ｖと
＋０．２Ｖの中間点；２．５Ｖ）に調整する（図６、７
参照）。(Prior Art 1) Microcomputer 10
Since the power supply voltage of 0 is usually 5 V, the upper limit / lower limit of the input voltage that the microcomputer 100 can process is 4.
It is 8V / 0.2V. Therefore, the gas sensor 101 is placed in an environment of normal temperature and humidity (temperature of about 25 ° C., humidity of about 60%), and the variable resistor 102 is adjusted and applied to the detection unit 103 in order to eliminate the displacement caused by Voltage is adjusted to adjust the terminal voltage Vs to the median value Vsc (intermediate point between + 4.8V and + 0.2V; 2.5V) (FIGS. 6 and 7).
reference).
【０００４】（従来技術２）ガスセンサ１０１を配設し
た室内の空気が汚染されていたり、環境状況（例えば、
夏季高温多湿時期）により端子電圧Ｖｓが低い場合に
は、マイクロコンピュータ１００はトランジスタ１０４
をオン状態に維持して抵抗１０５をショートし、検知部
１０３に、抵抗１０６を介して直流電圧を印加する（図
８参照）。(Prior Art 2) The air in the room where the gas sensor 101 is installed is contaminated, or the environmental conditions (for example,
When the terminal voltage Vs is low due to high temperature and high humidity in summer), the microcomputer 100 causes the transistor 104 to operate.
Is kept on and the resistor 105 is short-circuited, and a DC voltage is applied to the detection unit 103 via the resistor 106 (see FIG. 8).
【０００５】ガスセンサ１０１を配設した室内の空気の
清浄化が進行し、端子電圧Ｖｓが上昇してくると、マイ
クロコンピュータ１００がトランジスタ１０４をオフ状
態にして、検知部１０３に抵抗１０５、１０６を介して
直流電圧を印加し、端子電圧Ｖｓを引き下げる。尚、ガ
スセンサ１０１を配設した室内の空気の清浄化が進行し
ていても、環境状況（例えば、夏季高温多湿時期）によ
り端子電圧Ｖｓが低い場合にはマイクロコンピュータ１
００はトランジスタ１０４をオフ状態にしない。When the cleaning of the air in the room in which the gas sensor 101 is installed progresses and the terminal voltage Vs rises, the microcomputer 100 turns off the transistor 104, and the resistors 105 and 106 are connected to the detection unit 103. A DC voltage is applied through the terminal voltage Vs to lower the terminal voltage Vs. It should be noted that even if the cleaning of the air in the room where the gas sensor 101 is arranged is progressing, if the terminal voltage Vs is low due to environmental conditions (for example, high temperature and high humidity in summer), the microcomputer 1
00 does not turn off the transistor 104.
【０００６】[0006]
（従来技術１）上記の様に調整した半導体式のガスセン
サ１０１を、冬季乾燥時期（例えば温度１０℃、湿度３
０％）に使用する場合は、検知部１０３の抵抗値が調整
時より上がる為、検知部１０３の端子電圧Ｖｓは１Ｖ程
度、高い方に変位（Ｖｓｃ→Ｖｓ2 ）する。この状態で
は、清浄側のレンジは最大でも（４．８Ｖ−３．５Ｖ＝
１．３Ｖ）しか取れない。(Prior Art 1) The semiconductor-type gas sensor 101 adjusted as described above is used in the winter dry season (for example, temperature 10 ° C., humidity 3).
When used for 0%), the resistance value of the detection unit 103 is higher than that at the time of adjustment, so that the terminal voltage Vs of the detection unit 103 is displaced by about 1 V to the higher side (Vsc → Vs 2 ). In this state, the maximum range on the clean side is (4.8V-3.5V =
Only 1.3V).
【０００７】又、夏季高温多湿時期（例えば温度３０
℃、湿度７０％）に使用する場合は、検知部１０３の端
子電圧Ｖｓは１Ｖ程度、低い方に変位（Ｖｓｃ→Ｖ
ｓ1 ）する。この状態では、汚染側のレンジは最大でも
（１．５Ｖ−０．２Ｖ＝１．３Ｖ）しか取れない。つま
り、調整時と異なる環境下で半導体式のガスセンサを使
用すると、ダイナミックレンジが狭くなる。[0007] In addition, high temperature and high humidity in summer (for example, temperature 30
When it is used at a temperature of 70 ° C. and a humidity of 70%, the terminal voltage Vs of the detection unit 103 is about 1 V, which is displaced to the lower side (Vsc → V).
s 1 ) In this state, the range on the contaminated side can only take a maximum (1.5V-0.2V = 1.3V). In other words, if the semiconductor gas sensor is used in an environment different from that at the time of adjustment, the dynamic range becomes narrow.
【０００８】（従来技術２）上記、、に起因する
端子電圧Ｖｓの変位は解消できない。従来技術２では、
上記に起因する変位は或る程度解消できるが、これで
も、ダイナミックレンジは精々、３．５Ｖ程度である。(Prior Art 2) The displacement of the terminal voltage Vs caused by the above cannot be eliminated. In prior art 2,
Although the displacement caused by the above can be eliminated to some extent, the dynamic range is still about 3.5 V at best.
【０００９】本発明の目的は、環境条件（温度や湿度）
等に起因して検知部の端子電圧が高い方や低い方に変位
していても設定値に自動調節され、これにより広いダイ
ナミックレンジが確保できる汚染度合検出装置の提供に
ある。The object of the present invention is to consider environmental conditions (temperature and humidity).
The present invention provides a contamination degree detection device that can automatically adjust to a set value even if the terminal voltage of the detection unit is displaced to a higher or lower side due to the above, and thus can secure a wide dynamic range.
【００１０】[0010]
（請求項１の作用）電気ヒータが、金属酸化物からなる
検知部を加熱する。直流電源と検知部との間には、（入
力端子に）印加される電圧に対応して電気抵抗が変化す
る電圧- 抵抗変換素子が電気接続されている。(Operation of Claim 1) An electric heater heats a detection portion made of a metal oxide. A voltage-resistance conversion element whose electrical resistance changes according to the voltage applied (to the input terminal) is electrically connected between the DC power supply and the detection unit.
【００１１】調整用電圧制御手段は、ガスセンサが安定
状態になるまでの待機時間のあいだ、検知部の端子電圧
が設定値になる様に電圧- 抵抗変換素子に印加する調整
用電圧を調節するとともに、待機時間が終了すると調整
用電圧を前記待機時間の終了時点の値に固定する。空気
の汚れ具合に対応してガスセンサの検知部の電気抵抗値
が変化し、汚染度合検出手段は、待機時間終了後におけ
る検知部の端子電圧の変化に基づいて空気の汚れ具合を
検出する。The adjusting voltage control means adjusts the adjusting voltage applied to the voltage-resistance conversion element so that the terminal voltage of the detection unit becomes a set value during the waiting time until the gas sensor becomes stable. When the waiting time ends, the adjustment voltage is fixed to the value at the end of the waiting time. The electric resistance value of the detector of the gas sensor changes in accordance with the degree of contamination of the air, and the contamination degree detection means detects the degree of contamination of the air based on the change in the terminal voltage of the detector after the end of the waiting time.
【００１２】（請求項１の効果）汚染度合検出装置は、
ガスセンサが安定状態になるまでの待機時間のあいだ、
検知部の端子電圧が設定値になる様に電圧- 抵抗変換素
子に印加する調整用電圧を調整用電圧制御手段が調節
し、待機時間が終了すると調整用電圧を待機時間の終了
時点の値に固定する構成である。この為、温度や湿度の
環境条件等に起因して検知部の端子電圧が高い方や低い
方に変位していても、待機時間が終了した時点で検知部
の端子電圧が設定値に自動的に調整・固定されるので、
所定環境下（例えば温度２５℃、湿度６０％）での調整
が不要であり、手間がかからない。又、広いダイナミッ
クレンジが確保できるので、検出精度の向上が図れる。(Effect of Claim 1) The contamination degree detecting device is
During the waiting time until the gas sensor becomes stable,
The adjustment voltage control means adjusts the adjustment voltage applied to the voltage-resistance conversion element so that the terminal voltage of the detection unit becomes the set value, and when the standby time ends, the adjustment voltage is set to the value at the end of the standby time. It is a fixed structure. Therefore, even if the terminal voltage of the detection unit is displaced to the higher or lower side due to environmental conditions such as temperature and humidity, the terminal voltage of the detection unit will automatically reach the set value at the end of the waiting time. Will be adjusted and fixed to
There is no need for adjustment under a predetermined environment (for example, temperature 25 ° C., humidity 60%), and no trouble is required. Moreover, since a wide dynamic range can be secured, the detection accuracy can be improved.
【００１３】（請求項２の作用）電気ヒータが、金属酸
化物からなる検知部を加熱する。直流電源と検知部との
間には、発光部の発光量が多いほど受光素子の電気抵抗
が低くなるフォトカプラが電気接続されている。(Operation of Claim 2) The electric heater heats the detecting portion made of metal oxide. A photocoupler is electrically connected between the DC power source and the detection unit so that the electric resistance of the light receiving element decreases as the amount of light emitted from the light emitting unit increases.
【００１４】通電制御手段は、ガスセンサが安定状態に
なるまでの待機時間のあいだ、検知部の端子電圧が設定
値になる様に発光部への通電量を制御するとともに、待
機時間が終了すると通電量を待機時間の終了時点の値に
固定する。空気の汚れ具合に対応してガスセンサの検知
部の電気抵抗値が変化し、汚染度合検出手段は、待機時
間終了後における検知部の端子電圧の変化に基づいて空
気の汚れ具合を検出する。The energization control means controls the energization amount to the light emitting part so that the terminal voltage of the detection part becomes a set value during the waiting time until the gas sensor reaches a stable state, and energizes when the waiting time ends. The quantity is fixed at the value at the end of the waiting time. The electric resistance value of the detector of the gas sensor changes in accordance with the degree of contamination of the air, and the contamination degree detection means detects the degree of contamination of the air based on the change in the terminal voltage of the detector after the end of the waiting time.
【００１５】（請求項２の効果）汚染度合検出装置は、
ガスセンサが安定状態になるまでの待機時間のあいだ、
検知部の端子電圧が設定値になる様に発光部への通電量
を制御するとともに、待機時間が終了すると通電量を待
機時間の終了時点の値に固定する構成である。この為、
温度や湿度の環境条件等に起因して検知部の端子電圧が
高い方や低い方に変位していても、待機時間が終了した
時点で検知部の端子電圧が設定値に自動的に調整・固定
されるので、所定環境下（例えば温度２５℃、湿度６０
％）での調整が不要であり、手間がかからない。又、広
いダイナミックレンジが確保できるので、検出精度の向
上が図れる。(Effect of Claim 2) The contamination degree detecting device comprises:
During the waiting time until the gas sensor becomes stable,
The configuration is such that the energization amount to the light emitting unit is controlled so that the terminal voltage of the detection unit becomes the set value, and the energization amount is fixed to the value at the end time of the waiting time when the waiting time ends. Therefore,
Even if the terminal voltage of the detection unit is displaced to the higher or lower side due to environmental conditions such as temperature and humidity, the terminal voltage of the detection unit is automatically adjusted to the set value when the waiting time ends. Since it is fixed, it is in a predetermined environment (for example, temperature 25 ° C, humidity 60
%) Does not require adjustment and does not take much effort. Moreover, since a wide dynamic range can be secured, the detection accuracy can be improved.
【００１６】（請求項３の作用）待機時間が終了した時
点で調整用電圧が設定値に調整（固定）されているが、
待機時間経過後の空気の汚れ具合が待機時間中の空気の
汚れ具合に比べて大きく変化して来ると、検知部の端子
電圧が上限閾値以上か下限閾値以下になる（所定時間以
上継続）。(Operation of claim 3) The adjusting voltage is adjusted (fixed) to the set value at the end of the waiting time,
When the degree of air pollution after the waiting time has changed greatly compared to the degree of air pollution during the waiting time, the terminal voltage of the detection unit becomes equal to or higher than the upper threshold value or equal to or lower than the lower threshold value (continuous for a predetermined time or more).
【００１７】この状態になると、調整用電圧制御手段
は、検知部の端子電圧が設定値になる様に電圧- 抵抗変
換素子に印加する調整用電圧を再調節した後に調整用電
圧を固定する。尚、上記再調節期間のあいだは、汚染度
合を検出しない。汚染度合検出手段は、固定された各調
整用電圧の差と、再調節終了後における検知部の端子電
圧の変化とに基づいて空気の汚れ具合の検出を再開す
る。In this state, the adjusting voltage control means re-adjusts the adjusting voltage applied to the voltage-resistance conversion element so that the terminal voltage of the detecting section becomes the set value, and then fixes the adjusting voltage. The contamination level is not detected during the readjustment period. The contamination degree detection means restarts the detection of the degree of air pollution based on the fixed difference between the adjustment voltages and the change in the terminal voltage of the detection unit after the readjustment.
【００１８】（請求項３の効果）待機時間経過後の空気
の汚れ具合が待機時間中の空気の汚れ具合に比べて大き
く変化して、検知部の端子電圧が上限閾値以上か下限閾
値以下に所定時間継続すると、検知部の端子電圧が設定
値になる様に電圧- 抵抗変換素子に印加する調整用電圧
を調整用電圧制御手段が再調節した後に調整用電圧を固
定し、固定された各調整用電圧の差と、再調節終了後に
おける検知部の端子電圧の変化とに基づいて空気の汚れ
具合の検出を汚染度合検出手段が再開する構成であるの
で、更に広いダイナミックレンジが確保できる。(Effect of claim 3) The degree of contamination of air after the waiting time has largely changed as compared with the degree of contamination of air during the waiting time, and the terminal voltage of the detection unit becomes equal to or higher than the upper threshold value or lower than the lower threshold value. After continuing for a predetermined time, the adjustment voltage control means readjusts the adjustment voltage applied to the voltage-resistance conversion element so that the terminal voltage of the detection unit becomes the set value, and then the adjustment voltage is fixed. Since the contamination degree detecting means restarts the detection of the degree of contamination of the air based on the difference between the adjustment voltages and the change in the terminal voltage of the detection unit after the readjustment, a wider dynamic range can be secured.
【００１９】（請求項４の作用）ガスセンサは、空気の
汚れ具合に対応して電気抵抗値が変化する検知部と、発
熱して検知部を加熱する電気ヒータとを有する。電界効
果トランジスタのドレインを直流電源に接続し、ソース
を検知部に接続している。(Operation of Claim 4) The gas sensor has a detecting portion whose electric resistance value changes according to the degree of contamination of air, and an electric heater which generates heat to heat the detecting portion. The drain of the field effect transistor is connected to the DC power supply, and the source is connected to the detection unit.
【００２０】マイクロコンピュータは、ガスセンサが安
定状態になるまでの待機時間のあいだ、検知部の端子電
圧が設定値になる様にゲートに印加する調整用電圧を調
節するとともに、待機時間が終了すると調整用電圧を待
機時間の終了時点の値に固定し、待機時間終了後におけ
る検知部の端子電圧の変化に基づいて空気の汚れ具合を
検出する。The microcomputer adjusts the adjusting voltage applied to the gate so that the terminal voltage of the detection unit becomes the set value during the waiting time until the gas sensor becomes stable, and adjusts when the waiting time ends. The working voltage is fixed to the value at the end of the waiting time, and the degree of air pollution is detected based on the change in the terminal voltage of the detection unit after the waiting time ends.
【００２１】（請求項４の効果）温度や湿度の環境条件
等に起因して検知部の端子電圧がマイクロコンピュータ
の入力電圧範囲の中央値から高い方又は低い方にずれて
いても、待機時間が終了した時点で検知部の端子電圧が
設定値に自動的に調整・固定されるので、所定環境下
（例えば温度２５℃、湿度６０％）での調整が不要であ
り、手間がかからない。又、広いダイナミックレンジが
確保できるので、検出精度の向上が図れる。(Effect of Claim 4) Even if the terminal voltage of the detector deviates from the center value of the input voltage range of the microcomputer to the higher or lower side due to environmental conditions such as temperature and humidity, the waiting time Since the terminal voltage of the detection unit is automatically adjusted and fixed to the set value at the end of the step, adjustment under a predetermined environment (for example, temperature of 25 ° C. and humidity of 60%) is unnecessary, and it does not take time and effort. Moreover, since a wide dynamic range can be secured, the detection accuracy can be improved.
【００２２】（請求項５の作用）待機時間が終了した時
点で調整用電圧が設定値に調整（固定）されているが、
待機時間経過後の空気の汚れ具合が待機時間中の空気の
汚れ具合に比べて大きく変化して来ると、検知部の端子
電圧が上限閾値以上か下限閾値以下になる（所定時間以
上継続）。(Operation of claim 5) The adjustment voltage is adjusted (fixed) to the set value at the end of the waiting time.
When the degree of air pollution after the waiting time has changed greatly compared to the degree of air pollution during the waiting time, the terminal voltage of the detection unit becomes equal to or higher than the upper threshold value or equal to or lower than the lower threshold value (continuous for a predetermined time or more).
【００２３】この状態になると、マイクロコンピュータ
は、検知部の端子電圧が設定値になる様にゲートに印加
する調整用電圧を再調節した後に調整用電圧を固定す
る。尚、上記再調節期間のあいだは、汚染度合を検出し
ない。マイクロコンピュータは、固定された各調整用電
圧の差と、再調節後における検知部の端子電圧の変化と
に基づいて空気の汚れ具合の検出を再開する。In this state, the microcomputer re-adjusts the adjustment voltage applied to the gate so that the terminal voltage of the detection unit becomes the set value, and then fixes the adjustment voltage. The contamination level is not detected during the readjustment period. The microcomputer restarts detection of the degree of air pollution based on the fixed difference between the adjustment voltages and the change in the terminal voltage of the detection unit after readjustment.
【００２４】（請求項５の効果）待機時間経過後の空気
の汚れ具合が待機時間中の空気の汚れ具合に比べて大き
く変化して、検知部の端子電圧が上限閾値以上か下限閾
値以下に所定時間継続すると、マイクロコンピュータ
は、検知部の端子電圧が設定値になる様にゲートに印加
する調整用電圧を再調節した後に調整用電圧を固定し、
固定された各調整用電圧の差と、再調節後における検知
部の端子電圧の変化とに基づいて空気の汚れ具合の検出
を再開する構成であるので、更に広いダイナミックレン
ジが確保できる。(Effect of claim 5) The degree of contamination of air after the waiting time has changed greatly compared to the degree of contamination of air during the waiting time, and the terminal voltage of the detection section becomes equal to or higher than the upper threshold value or lower than the lower threshold value. After continuing for a predetermined time, the microcomputer re-adjusts the adjustment voltage applied to the gate so that the terminal voltage of the detection unit becomes the set value, and then fixes the adjustment voltage,
Since the detection of the degree of air contamination is restarted based on the fixed difference between the adjustment voltages and the change in the terminal voltage of the detection unit after readjustment, a wider dynamic range can be secured.
【００２５】（請求項６の作用）ガスセンサが安定状態
になるまでの待機時間中に、マイクロコンピュータは、
電圧が比較的高いＨｉ状態と、電圧が比較的低いＬｏ状
態とが反復するパルスをゲートに印加するとともに、検
知部の端子電圧（温度や湿度の環境条件等により変位す
る）がマイクロコンピュータの入力電圧範囲の中央値に
なる様にＨｉ状態時間を調節する。そして、待機時間が
終了すると、マイクロコンピュータは、Ｈｉ状態時間を
待機時間の終了時点の値に固定し、検知部の端子電圧の
変化に基づいて空気の汚れ具合を判定する。(Operation of Claim 6) During the waiting time until the gas sensor reaches a stable state, the microcomputer is
A pulse in which a Hi state with a relatively high voltage and a Lo state with a relatively low voltage are repeated is applied to the gate, and the terminal voltage of the detector (displaced due to environmental conditions such as temperature and humidity) is input to the microcomputer. The Hi state time is adjusted so that it becomes the median value of the voltage range. When the waiting time ends, the microcomputer fixes the Hi state time to the value at the end of the waiting time, and determines the degree of air pollution based on the change in the terminal voltage of the detection unit.
【００２６】（請求項６の効果）待機中に、温度や湿度
の環境条件等に起因して検知部の端子電圧が、マイクロ
コンピュータの入力電圧範囲の上方又は下方に変位して
いると、マイクロコンピュータにより端子電圧が入力電
圧範囲の中央値に自動的に調節・固定されるので、所定
環境下（例えば温度２５℃、湿度６０％）での調整が不
要であり、手間がかからない。又、広いダイナミックレ
ンジが確保できるので、検出精度の向上が図れる。(Effect of claim 6) During standby, if the terminal voltage of the detection unit is displaced above or below the input voltage range of the microcomputer due to environmental conditions such as temperature and humidity, Since the terminal voltage is automatically adjusted / fixed to the center value of the input voltage range by the computer, the adjustment under a predetermined environment (for example, temperature 25 ° C., humidity 60%) is unnecessary, and it does not take time and effort. Moreover, since a wide dynamic range can be secured, the detection accuracy can be improved.
【００２７】[0027]
【発明の実施の形態】本発明の第１実施例（請求項１、
４、６に対応）を、図１〜図４に基づいて説明する。図
１に示す様に、汚染度合検出装置Ａは、感応体部１１及
び電気ヒータ１２を有するガスセンサ１と、ドレイン２
１を＋５Ｖに接続し、ソース２２を感応体部１１に接続
したＦＥＴ（電界効果トランジスタ）２と、ゲート２３
に抵抗３１を介して調整用電圧Ｖａを送出するととも
に、感応体部１１の端子電圧Ｖｓの変化に基づいて空気
の汚れ具合を判定するマイクロコンピュータ３とを備え
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention (Claim 1,
4 and 6) will be described with reference to FIGS. As shown in FIG. 1, the contamination degree detecting device A includes a gas sensor 1 having a sensitive body portion 11 and an electric heater 12, and a drain 2.
FET (field effect transistor) 2 in which 1 is connected to +5 V and source 22 is connected to the sensitive body portion 11, and gate 23
Further, the microcomputer 3 is provided with the adjustment voltage Va via the resistor 31 and determines the degree of air pollution based on the change in the terminal voltage Vs of the sensitive body 11.
【００２８】ガスセンサ１は、汚染物質の付着量が多く
なる程、電気抵抗が低くなる｛５ｋΩ〜４０ｋΩ→１．
５ｋΩ〜１２ｋΩ｝感応体部１１（貴金属酸化物質の半
導体；例えば、主成分ＳｎＯ2 に少量の貴金属を添加し
たもの）と、通電により発熱して感応体部１１を作動温
度（４００℃〜４８０℃）に加熱する電気ヒータ１２と
を有する。The gas sensor 1 has a lower electric resistance as the amount of adhered pollutants increases {5 kΩ to 40 kΩ → 1.
5 kΩ to 12 kΩ} sensitive part 11 (semiconductor of noble metal oxide substance; for example, a small amount of noble metal added to main component SnO 2 ) and heat generated by energization to cause the sensitive part 11 to operate at an operating temperature (400 ° C. to 480 ° C.). ) And an electric heater 12 for heating.
【００２９】ＦＥＴ２は、ドレイン２１を＋５Ｖに接続
し、ソース２２を感応体部１１に接続している。又、ゲ
ート２３にはコンデンサ２４及び抵抗３１の一端が接続
されている。マイクロコンピュータ３は、受電端子３
２、３３が、各々、＋５Ｖ、ＧＮＤに接続され、Ｉ／Ｏ
ポート３４から調整用電圧Ｖａが抵抗３１を介してゲー
ト２３に送出され（ゲート電圧Ｖｇ）、感応体部１１の
端子電圧ＶｓがＡ／Ｄ入力ポート３５に入力されてい
る。In the FET 2, the drain 21 is connected to + 5V and the source 22 is connected to the sensitive body portion 11. Further, one end of a capacitor 24 and a resistor 31 is connected to the gate 23. The microcomputer 3 has a power receiving terminal 3
2, 33 are connected to + 5V and GND, respectively, and I / O
The adjustment voltage Va is sent from the port 34 to the gate 23 via the resistor 31 (gate voltage Vg), and the terminal voltage Vs of the sensitive body 11 is input to the A / D input port 35.
【００３０】つぎに、汚染度合検出装置Ａの作動を、図
２〜図４に基づいて説明する。電源をオンすると、ステ
ップｓ１で、マイクロコンピュータ３は、調整用電圧Ｖ
ａの送出を開始する。尚、調整用電圧Ｖａは、本実施例
では、周期Ｔを固定して、電圧が比較的高い（例えば２
Ｖ）Ｈｉ状態時間（数百μｓ〜数十ｍｓの時間間隔ｔ）
と、電圧が比較的低い（例えば０．５Ｖ）Ｌｏ状態時間
｛即ちＨｉ状態とは異なる時間間隔（Ｔ−ｔ）｝とが反
復するパルスである（図３参照）。Next, the operation of the contamination degree detecting device A will be described with reference to FIGS. When the power is turned on, in step s1, the microcomputer 3 sets the adjustment voltage V
Start sending a. In the present embodiment, the adjustment voltage Va has a relatively high voltage (for example, 2 when the cycle T is fixed).
V) Hi state time (time interval t of several hundred μs to several tens ms)
And a Lo state time (that is, a time interval (T−t) different from the Hi state) with a relatively low voltage (for example, 0.5 V) are repeated pulses (see FIG. 3).
【００３１】ステップｓ２で、待機時間（電源オンから
３０秒間）が終了しているか否かを判別し、終了してい
ない場合（ＮＯ）はステップｓ３に進む。又、終了して
いる場合（ＹＥＳ）はステップｓ４に進む。In step s2, it is determined whether or not the waiting time (30 seconds after the power is turned on) has ended. If not (NO), the process proceeds to step s3. If it has ended (YES), the process proceeds to step s4.
【００３２】ステップｓ３で、マイクロコンピュータ３
は、感応体部１１の端子電圧Ｖｓが＋２．５Ｖ｛（マイ
クロコンピュータ３の入力電圧範囲（＋０．２Ｖ〜＋
４．８Ｖ）の中央値｝になる様に、調整用電圧ＶａのＨ
ｉ状態時間ｔを調節する。At step s3, the microcomputer 3
Indicates that the terminal voltage Vs of the sensitive part 11 is +2.5 V {(input voltage range of the microcomputer 3 (+0.2 V to +
(Median value of 4.8 V)} H of the adjustment voltage Va
Adjust i-state time t.
【００３３】感応体部１１の電気抵抗が大きい冬季乾燥
時期には、感応体部１１の端子電圧Ｖｓは高いので、調
整用電圧ＶａのＨｉ状態時間ｔは短く（数百μｓ）設定
される（図３上側、図４の実線参照）。又、感応体部１
１の電気抵抗が小さい夏季高温多湿時期には、感応体部
１１の端子電圧Ｖｓは低いので、調整用電圧ＶａのＨｉ
状態時間ｔは長く（数十ｍｓ）設定される（図３下側、
図４の二点鎖線参照）。Since the terminal voltage Vs of the sensitive portion 11 is high during the dry season in winter when the electrical resistance of the sensitive portion 11 is large, the Hi state time t of the adjustment voltage Va is set short (several hundred μs) ( 3 upper side, see the solid line in FIG. 4). In addition, the sensitive part 1
Since the terminal voltage Vs of the sensitive portion 11 is low during the high temperature and high humidity in summer when the electric resistance of 1 is small, the adjustment voltage Va is Hi.
The state time t is set long (several tens of ms) (the lower side of FIG. 3,
(See the chain double-dashed line in FIG. 4).
【００３４】ステップｓ４で、マイクロコンピュータ３
は、調整用電圧ＶａのＨｉ状態時間ｔを、待機時間の終
了時点の値に固定する。ステップｓ５で、感応体部１１
の端子電圧Ｖｓの変化に基づいて、汚染度合の判定動作
を開始する。At step s4, the microcomputer 3
Fixes the Hi state time t of the adjustment voltage Va to the value at the end of the waiting time. In step s5, the sensitive part 11
Based on the change in the terminal voltage Vs of 1, the contamination level determination operation is started.
【００３５】例えば、所定時間（数ｍｓ〜数百ｍｓ）毎
に端子電圧Ｖｓをサンプリングし、過去２分間にサンプ
リングした端子電圧Ｖｓの平均値と最も新しいサンプリ
ング時点の端子電圧Ｖｓとを演算処理し抵抗比に変換す
る。例えば、抵抗比＜汚染判定閾値の場合に、“室内が
汚染状態にある”と判定し、空気清浄機等を作動状態に
する。For example, the terminal voltage Vs is sampled every predetermined time (several ms to several hundred ms), and the average value of the terminal voltages Vs sampled in the past 2 minutes and the terminal voltage Vs at the latest sampling time are calculated. Convert to resistance ratio. For example, when the resistance ratio <contamination determination threshold value, it is determined that "the room is in a polluted state" and the air purifier or the like is activated.
【００３６】つぎに、本実施例の利点を述べる。 〔ア〕汚染度合検出装置Ａは、温度や湿度の環境条件等
により変位する感応体部１１の端子電圧Ｖｓを、マイク
ロコンピュータ３が調整用電圧ＶａのＨｉ状態を略無段
階に調節して、端子電圧Ｖｓを２．５Ｖ（マイクロコン
ピュータ３の入力電圧範囲の中央）に自動制御する構成
である。この為、常温常湿の環境下での調整（可変抵抗
器等による調整）が不要であり、手間がかからない。Next, the advantages of this embodiment will be described. [A] In the contamination degree detection device A, the microcomputer 3 adjusts the terminal voltage Vs of the responsive body portion 11 which is displaced by environmental conditions such as temperature and humidity in a Hi state of the adjustment voltage Va in a substantially stepless manner, The terminal voltage Vs is automatically controlled to 2.5 V (the center of the input voltage range of the microcomputer 3). Therefore, adjustment (adjustment with a variable resistor or the like) in an environment of normal temperature and normal humidity is not necessary, which saves labor.
【００３７】〔イ〕電源スイッチをオンしてからガスセ
ンサ１が安定状態になるまでの待機時間中に、マイクロ
コンピュータ３は、感応体部１１の端子電圧Ｖｓが低い
（夏季高温多湿時期）ほど調整用電圧ＶａのＨｉ状態時
間ｔを長くし、端子電圧Ｖｓが高い（冬季乾燥時期）ほ
ど調整用電圧ＶａのＨｉ状態時間ｔを短くして、端子電
圧Ｖｓを２．５Ｖ（マイクロコンピュータ３の入力電圧
範囲の中央）に調節する構成である。[A] During the waiting time until the gas sensor 1 becomes stable after the power switch is turned on, the microcomputer 3 adjusts as the terminal voltage Vs of the sensitive part 11 becomes lower (summer high temperature and high humidity season). The Hi state time t of the adjustment voltage Va is set to be longer, and the Hi state time t of the adjustment voltage Va is set to be shorter as the terminal voltage Vs is higher (winter dry season), and the terminal voltage Vs is set to 2.5 V (input of the microcomputer 3). The center of the voltage range) is adjusted.
【００３８】つまり、温度や湿度の環境条件等に起因し
て感応体部１１の端子電圧Ｖｓが変位していても、マイ
クロコンピュータ３によって、調整用電圧ＶａのＨｉ状
態時間が調節されて＋２．５Ｖに調節されるので、広い
ダイナミックレンジＤ1 （０．２Ｖ〜４．８Ｖ）が確保
でき、検出精度の向上が図れる。That is, even if the terminal voltage Vs of the responsive body portion 11 is changed due to environmental conditions such as temperature and humidity, the microcomputer 3 adjusts the Hi state time of the adjustment voltage Va to +2. Since the voltage is adjusted to 5V, a wide dynamic range D 1 (0.2V to 4.8V) can be secured and detection accuracy can be improved.
【００３９】〔ウ〕ＦＥＴ２をパルス駆動して、感応体
部１１の端子電圧Ｖｓを調整する構成であるので、抵抗
３１を介してマイクロコンピュータ３がＦＥＴ２を直接
駆動することができ、回路が簡単であり、安価にでき
る。[C] Since the FET2 is pulse-driven to adjust the terminal voltage Vs of the sensitive body portion 11, the microcomputer 3 can directly drive the FET2 via the resistor 31, and the circuit is simple. And can be cheap.
【００４０】本発明は、上記実施例以外に、つぎの実施
態様を含む。 ａ．図１のＦＥＴ２に替え、図５に示す様に、＋５Ｖと
感応体部１１との間に、入光量が多いほど電気抵抗が低
くなり、入光量が少ないほど受光素子４１の電気抵抗が
高くなる、フォトカプラ４の受光素子４１を電気接続
し、マイクロコンピュータ３が、通電制御回路５を介し
てフォトカプラ４の発光部４２に通電される電力量を制
御するとともに、感応体部１１の端子電圧の変化に基づ
いて空気の汚れ具合を判定する構成であっても良い（請
求項２に対応）。The present invention includes the following embodiments in addition to the above embodiment. a. As shown in FIG. 5, in place of the FET 2 in FIG. 1, the electric resistance between +5 V and the sensitive body portion 11 decreases as the amount of incident light increases, and the electric resistance of the light receiving element 41 increases as the amount of incident light decreases. , The light receiving element 41 of the photocoupler 4 is electrically connected, and the microcomputer 3 controls the amount of power supplied to the light emitting section 42 of the photocoupler 4 via the energization control circuit 5 and the terminal voltage of the sensitive body section 11. The configuration may be such that the degree of contamination of the air is determined based on the change of (corresponding to claim 2).
【００４１】ｂ．上記実施例において、待機時間終了後
（図２のステップｓ５）において検知部の端子電圧が上
限閾値以上（例えば４Ｖ以上）か下限閾値以下（例えば
１Ｖ以下）の状態が所定時間（数分〜数十分）継続する
と、マイクロコンピュータ３が、感応体部１１の端子電
圧Ｖｓが＋２．５Ｖ（設定値）になる様に調整用電圧Ｖ
ａのＨｉ状態時間ｔを再調節した後に調整用電圧Ｖａの
Ｈｉ状態時間ｔを固定し、固定された各調整用電圧のＨ
ｉ状態時間ｔの差と、再調節終了後における感応体部１
１の端子電圧Ｖｓの変化とに基づいて空気の汚れ具合の
検出を再開する構成であっても良い（請求項３、５に対
応）。B. In the above-described embodiment, after the waiting time ends (step s5 in FIG. 2), the terminal voltage of the detection unit is equal to or higher than the upper threshold (eg, 4 V or more) or lower than the lower threshold (eg, 1 V or less) for a predetermined time (several minutes to several minutes). Sufficiently), the microcomputer 3 adjusts the voltage Vs for adjustment so that the terminal voltage Vs of the sensitive part 11 becomes + 2.5V (set value).
After the readjustment of the Hi state time t of a, the Hi state time t of the adjustment voltage Va is fixed, and the H of each fixed adjustment voltage H is fixed.
The difference between the i-state time t and the sensor unit 1 after readjustment
Alternatively, the detection of the degree of air pollution may be restarted based on the change in the terminal voltage Vs of No. 1 (corresponding to claims 3 and 5).
【００４２】ｃ．図１の実施例では、マイクロコンピュ
ータ３がＦＥＴ２をパルス駆動して感応体部１１の端子
電圧Ｖｓを調整する構成であるが、ＦＥＴ２のゲートに
印加する電圧を変化させて端子電圧Ｖｓを調整する構成
に変更しても良い。C. In the embodiment of FIG. 1, the microcomputer 3 pulse-drives the FET 2 to adjust the terminal voltage Vs of the sensitive body portion 11. However, the terminal voltage Vs is adjusted by changing the voltage applied to the gate of the FET 2. The configuration may be changed.
【００４３】ｄ．フォトカプラには、ＣｄＳ、ＣｄＳ
ｅ、抵抗式フォトカプラ、フォトトランジスタ、フォト
ダイオード等が使用できる。D. CdS, CdS for the photo coupler
e, a resistance type photocoupler, a phototransistor, a photodiode or the like can be used.
【図１】本発明に係る汚染度合検出装置の概略電気回路
図である。FIG. 1 is a schematic electric circuit diagram of a contamination degree detection device according to the present invention.
【図２】その汚染度合検出装置のマイクロコンピュータ
の作動を示すフローチャートである。FIG. 2 is a flowchart showing an operation of a microcomputer of the contamination degree detecting device.
【図３】冬季乾燥時期、又は夏季高温多湿時期におい
て、マイクロコンピュータが送出する調整用電圧Ｖａ
と、ＦＥＴのゲートに印加されるゲート電圧Ｖｇの波形
である。FIG. 3 is an adjustment voltage Va sent by a microcomputer during a dry season in winter or a hot and humid season in summer.
And the waveform of the gate voltage Vg applied to the gate of the FET.
【図４】調整用電圧Ｖａの変化の様子を示すグラフであ
る。FIG. 4 is a graph showing how the adjustment voltage Va changes.
【図５】本発明の他の実施例に係る汚染度合検出装置の
概略電気回路図である。FIG. 5 is a schematic electric circuit diagram of a pollution degree detection device according to another embodiment of the present invention.
【図６】従来技術の汚染度合検出装置において、ガスセ
ンサの感応体部の端子電圧の変動動向を示すグラフであ
る。FIG. 6 is a graph showing the trend of fluctuations in the terminal voltage of the sensitive part of the gas sensor in the conventional pollution degree detection device.
【図７】従来技術１の汚染度合検出装置の概略電気回路
図である。FIG. 7 is a schematic electric circuit diagram of a contamination degree detecting device according to the related art 1.
【図８】従来技術２の汚染度合検出装置の概略電気回路
図である。FIG. 8 is a schematic electric circuit diagram of a contamination degree detecting device according to the related art 2.
１ ガスセンサ ２ ＦＥＴ（電圧- 抵抗変換素子、電界効果トランジス
タ） ３ マイクロコンピュータ ４ フォトカプラ １１ 感応体部（検知部） １２ 電気ヒータ ２１ ドレイン ２２ ソース ２３ ゲート ３１ 抵抗 ４１ 受光素子 ４２ 発光部 Ａ 汚染度合検出装置 Ｖａ 調整用電圧 Ｖｓ 端子電圧1 Gas Sensor 2 FET (Voltage-Resistance Conversion Element, Field Effect Transistor) 3 Microcomputer 4 Photocoupler 11 Sensitive Part (Detection Part) 12 Electric Heater 21 Drain 22 Source 23 Gate 31 Resistor 41 Light-Receiving Element 42 Light-Emitting Part A Contamination Degree Detection Device Va adjustment voltage Vs terminal voltage
Claims (6)
変化する金属酸化物からなる検知部、及び該検知部を加
熱する電気ヒータを有するガスセンサと、 直流電源と前記検知部との間に電気接続され、印加され
る電圧に対応して電気抵抗が変化する電圧- 抵抗変換素
子と、 前記ガスセンサが安定状態になるまでの待機時間のあい
だ前記検知部の端子電圧が設定値になる様に前記電圧-
抵抗変換素子に印加する調整用電圧を調節するととも
に、前記待機時間が終了すると前記調整用電圧を前記待
機時間の終了時点の値に固定する調整用電圧制御手段
と、 待機時間終了後における前記検知部の端子電圧の変化に
基づいて空気の汚れ具合を検出する汚染度合検出手段と
を備える汚染度合検出装置。1. A gas sensor having a detection part made of metal oxide whose electric resistance value changes according to the degree of contamination of air, and a gas sensor having an electric heater for heating the detection part, and between a direct current power supply and the detection part. The terminal voltage of the detection unit is set to the set value during the waiting time until the gas sensor becomes stable and the voltage-resistance conversion element that is electrically connected to the voltage sensor and the electric resistance changes according to the applied voltage. To the voltage-
Adjusting voltage control means for adjusting the adjusting voltage applied to the resistance conversion element and fixing the adjusting voltage to the value at the end of the waiting time when the waiting time ends, and the detection after the waiting time ends Contamination level detecting device for detecting the degree of contamination of air based on a change in the terminal voltage of the section.
変化する金属酸化物からなる検知部、及び該検知部を加
熱する電気ヒータを有するガスセンサと、 直流電源と前記検知部との間に電気接続され、発光部の
発光量が多いほど受光素子の電気抵抗が低くなるフォト
カプラと、 前記ガスセンサが安定状態になるまでの待機時間のあい
だ前記検知部の端子電圧が設定値になる様に前記発光部
への通電量を制御するとともに、前記待機時間が終了す
ると前記通電量を前記待機時間の終了時点の値に固定す
る通電制御手段と、 待機時間終了後における前記検知部の端子電圧の変化に
基づいて空気の汚れ具合を検出する汚染度合検出手段と
を備える汚染度合検出装置。2. A gas sensor having a detection part made of a metal oxide whose electric resistance value changes according to the degree of contamination of air, and a gas sensor having an electric heater for heating the detection part, and between a DC power supply and the detection part. The photocoupler is electrically connected to the photocoupler, and the electric resistance of the light receiving element decreases as the amount of light emitted from the light emitting unit increases, and the terminal voltage of the detection unit is set to the set value during the standby time until the gas sensor becomes stable. And an energization control means for controlling the energization amount to the light emitting part and fixing the energization amount to a value at the end time of the waiting time when the waiting time ends, and a terminal voltage of the detecting part after the waiting time ends. And a contamination degree detecting device for detecting the degree of contamination of the air based on the change of the contamination degree.
了後において前記検知部の端子電圧が上限閾値以上か下
限閾値以下の状態が所定時間継続すると、前記検知部の
端子電圧が設定値になる様に前記電圧- 抵抗変換素子に
印加する調整用電圧を再調節した後に前記調整用電圧を
固定し、 前記汚染度合検出手段は、固定された各調整用電圧の差
と、再調節終了後における前記検知部の端子電圧の変化
とに基づいて空気の汚れ具合の検出を再開する請求項１
に記載の汚染度合検出装置。3. The adjusting voltage control means sets the terminal voltage of the detection unit to a set value when the terminal voltage of the detection unit is equal to or higher than an upper threshold value and equal to or lower than a lower threshold value for a predetermined time after the standby time ends. So that the adjustment voltage to be applied to the voltage-resistance conversion element is readjusted and then the adjustment voltage is fixed, and the contamination degree detection means is configured to detect the difference between the fixed adjustment voltages and after the readjustment is completed. 2. The detection of the degree of contamination of air is restarted based on the change in the terminal voltage of the detection unit in step 1.
The contamination degree detection device described in.
変化する金属酸化物からなる検知部、及び該検知部を加
熱する電気ヒータを有するガスセンサと、 ドレインを直流電源に接続し、ソースを前記検知部に接
続し、ゲートに印加される電圧に対応して電気抵抗が変
化する電界効果トランジスタと、 前記ガスセンサが安定状態になるまでの待機時間のあい
だ前記検知部の端子電圧が設定値になる様に前記ゲート
に印加する調整用電圧を調節するとともに、前記待機時
間が終了すると前記調整用電圧を前記待機時間の終了時
点の値に固定し、待機時間終了後における前記検知部の
端子電圧の変化に基づいて空気の汚れ具合を検出するマ
イクロコンピュータとを備える汚染度合検出装置。4. A gas sensor having a detection part made of a metal oxide whose electric resistance value changes according to the degree of contamination of air, and an electric heater for heating the detection part; a drain connected to a DC power source; A field effect transistor whose electric resistance changes in response to a voltage applied to the gate, and a terminal voltage of the detection unit during a standby time until the gas sensor reaches a stable state. The adjusting voltage applied to the gate is adjusted so that when the waiting time ends, the adjusting voltage is fixed to the value at the end time of the waiting time, and the terminal of the detection unit after the waiting time ends. A contamination degree detection device comprising: a microcomputer that detects the degree of contamination of air based on a change in voltage.
終了後において前記検知部の端子電圧が上限閾値以上か
下限閾値以下の状態が所定時間継続すると、前記検知部
の端子電圧が設定値になる様に前記調整用電圧を再調節
した後に前記調整用電圧を固定し、固定された各調整用
電圧の差と待機時間終了後における前記検知部の端子電
圧の変化とに基づいて空気の汚れ具合の検出を再開する
請求項４に記載の汚染度合検出装置。5. The microcomputer is configured such that the terminal voltage of the detection unit is set to a set value when the terminal voltage of the detection unit is equal to or higher than an upper threshold value and equal to or lower than a lower threshold value for a predetermined time after the end of the waiting time. After the readjustment of the adjustment voltage, the adjustment voltage is fixed, and the degree of air pollution is detected based on the difference between the fixed adjustment voltages and the change in the terminal voltage of the detection unit after the waiting time ends. The pollution degree detection device according to claim 4, wherein
ｉ状態と、電圧が比較的低いＬｏ状態とが反復するパル
スであり、 前記設定値は、前記マイクロコンピュータの入力電圧範
囲の中央値である請求項４又は請求項５に記載の汚染度
合検出装置。6. The adjusting voltage is H, which has a relatively high voltage.
The contamination level detection device according to claim 4 or 5, wherein the i-state and the Lo-state having a relatively low voltage are repeated pulses, and the set value is a median value of an input voltage range of the microcomputer. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12286596A JPH09304320A (en) | 1996-05-17 | 1996-05-17 | Detecting device for degree of pollution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12286596A JPH09304320A (en) | 1996-05-17 | 1996-05-17 | Detecting device for degree of pollution |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09304320A true JPH09304320A (en) | 1997-11-28 |
Family
ID=14846554
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12286596A Pending JPH09304320A (en) | 1996-05-17 | 1996-05-17 | Detecting device for degree of pollution |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09304320A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6714876B2 (en) | 2000-02-28 | 2004-03-30 | Ngk Spark Plug Co., Ltd. | Control system |
| US6756571B2 (en) * | 2002-10-17 | 2004-06-29 | Hitachi, Ltd. | System and method for compensation of contamination of a heated element in a heated element gas flow sensor |
-
1996
- 1996-05-17 JP JP12286596A patent/JPH09304320A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6714876B2 (en) | 2000-02-28 | 2004-03-30 | Ngk Spark Plug Co., Ltd. | Control system |
| US6756571B2 (en) * | 2002-10-17 | 2004-06-29 | Hitachi, Ltd. | System and method for compensation of contamination of a heated element in a heated element gas flow sensor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8598859B2 (en) | Power supply controller | |
| US5694208A (en) | Sensor for detecting fine particles such as smoke or dust contained in the air | |
| JPS61290465A (en) | Temperature controller for fixing device | |
| US4585339A (en) | Power control of electronic apparatus in response to surrounding brightness | |
| JPH09304320A (en) | Detecting device for degree of pollution | |
| KR930002444Y1 (en) | Air cleaner controlling circuit | |
| WO1988001728A1 (en) | Temperature sensing element | |
| KR100363576B1 (en) | Gas detection method and gas detection device using the same | |
| JPH0341220Y2 (en) | ||
| JPS6088662A (en) | Hot wire controller for car hot-wire-built-in glass | |
| KR920000605Y1 (en) | Humidifier | |
| JP2003059623A (en) | Current control method, and current control device for practicing current control method | |
| KR890001217Y1 (en) | Heating circuit of bidet | |
| JP2581038B2 (en) | Timer circuit | |
| JPH06331584A (en) | Environmental sensor | |
| JPH0447323B2 (en) | ||
| JP2004152627A (en) | Current control method and current control device to implement above | |
| KR0141045B1 (en) | Seat temperature control device for a car | |
| KR100240169B1 (en) | Photo intensity controller | |
| JPH04360415A (en) | Photoelectric switch | |
| KR940003815Y1 (en) | Temperature control circuit | |
| RU2390850C2 (en) | Heat fire detector | |
| JPH0447636Y2 (en) | ||
| JPH071413B2 (en) | Method and device for controlling fixing device in electrophotographic recording apparatus | |
| JPH03286925A (en) | Cooking device |