JP2885581B2 - Temperature and humidity detection circuit - Google Patents
Temperature and humidity detection circuitInfo
- Publication number
- JP2885581B2 JP2885581B2 JP22888792A JP22888792A JP2885581B2 JP 2885581 B2 JP2885581 B2 JP 2885581B2 JP 22888792 A JP22888792 A JP 22888792A JP 22888792 A JP22888792 A JP 22888792A JP 2885581 B2 JP2885581 B2 JP 2885581B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- sensitive
- resistor
- humidity
- resistance
- 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.)
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- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は温湿度検出回路に関し、
詳しくは、特に加熱調理装置の絶体湿度及び温度検出を
兼用する温湿度検出回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature and humidity detecting circuit,
More particularly, the present invention relates to a temperature / humidity detection circuit that also serves to detect the absolute humidity and temperature of a cooking device.
【０００２】[0002]
【従来の技術】図６は従来例１の湿度検出回路である。
図６に示すように、Ｒsは湿気を含む雰囲気に暴露され
湿度変化を検出する第１感温抵抗素子、Ｒrはその雰囲
気の温度変化を検出する第２感温抵抗素子、Ａ1はオペ
アンプ、Ｒ1、Ｒ2は固定抵抗である。Ｅvはこの湿度検
出回路に供給される直流定電圧であり、Ｅoは固定抵抗
Ｒ 1、Ｒ2で決定される基準電圧である。Ｉo（＝Ｅo/Ｒ
r）は第１感温抵抗素子Ｒs及び第２感温抵抗素子Ｒr に
流れる電流値である。この時の絶対湿度値を示す出力Ｖ
out は次式で示される。 Ｖout ＝(１＋Ｒs/Ｒr)×Ｅo2. Description of the Related Art FIG. 6 shows a humidity detection circuit of a first conventional example.
As shown in FIG. 6, Rs was exposed to an atmosphere containing moisture.
The first temperature-sensitive resistance element for detecting a change in humidity, Rr, represents the atmosphere.
A second temperature-sensitive resistance element for detecting a temperature change of air, A1Is an operation
Amplifier, R1, RTwoIs a fixed resistance. Ev is the humidity detection
DC constant voltage supplied to the output circuit, Eo is a fixed resistance
R 1, RTwoIs the reference voltage determined by Io (= Eo / R
r) corresponds to the first temperature-sensitive resistor Rs and the second temperature-sensitive resistor Rr.
It is the value of the flowing current. Output V indicating absolute humidity value at this time
out is represented by the following equation. Vout = (1 + Rs / Rr) × Eo
【０００３】図７は従来例２の湿度検出回路である。図
７に示すように、図６の回路にオペアンプＡ2、固定抵
抗Ｒ3〜Ｒ5で構成される演算増幅回路を追加した例であ
り、この時の絶対湿度値を示す出力Ｖoutは次式で示さ
れる。 Ｖout ＝−(Ｒs/Ｒr)×(Ｒ5/Ｒ3)×Ｅo ＋(１＋Ｒ5/
Ｒ4)×ＥoFIG. 7 shows a humidity detection circuit of a second conventional example. As shown in FIG. 7, this is an example in which an operational amplifier composed of an operational amplifier A 2 and fixed resistors R 3 to R 5 is added to the circuit of FIG. 6. The output Vout indicating the absolute humidity value at this time is expressed by the following equation. Indicated by Vout = − (Rs / Rr) × (R 5 / R 3 ) × Eo + (1 + R 5 /
R 4 ) × Eo
【０００４】第１、第２感温抵抗素子は略同一温度で少
なくとも１００℃以上に加熱されるように構成された感
温抵抗素子を利用した湿度検出回路においては、感温抵
抗素子は、通常、少なくとも水の沸点温度以上に自己加
熱させられている。このような温度で自己加熱している
第１感温抵抗素子は雰囲気温度の変化による抵抗値変化
の外にその時の絶体湿度量に応じた抵抗値変化を示す。
すなわち湿度量が多いと自己加熱温度が湿度により冷却
され雰囲気温度より低くなる。従って上記の式でも示さ
れるように第１の感温抵抗素子と第２の感温抵抗素子の
抵抗比を電圧変換することで雰囲気温度を補正しつつ絶
対湿度量を検出する方式が知られている。In a humidity detecting circuit using a temperature-sensitive resistance element configured so that the first and second temperature-sensitive resistance elements are heated to at least 100 ° C. at substantially the same temperature, the temperature-sensitive resistance element is usually , At least to the boiling point of water. The first temperature-sensitive resistance element that is self-heated at such a temperature exhibits a resistance value change according to the absolute humidity at that time, in addition to a resistance value change due to a change in ambient temperature.
That is, when the humidity is large, the self-heating temperature is cooled by the humidity and becomes lower than the ambient temperature. Therefore, a method of detecting the absolute humidity while correcting the ambient temperature by converting the resistance ratio of the first temperature-sensitive resistance element to the resistance value of the second temperature-sensitive resistance element as shown in the above equation is known. I have.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、上記の
ように構成された従来の湿度検出回路では、絶対湿度量
を検出できても温度変化を検出することはできなかっ
た。従って、温度測定が必要な場合は新たな温度測定装
置を設ける必要であった。However, in the conventional humidity detecting circuit constructed as described above, a change in temperature cannot be detected even if the absolute humidity amount can be detected. Therefore, when temperature measurement is required, it is necessary to provide a new temperature measuring device.
【０００６】[0006]
【課題を解決するための手段】本発明には以下に示す３
種類の発明がある。第１の発明は、第１および第２感温
抵抗素子を具備し、第１感温抵抗素子を雰囲気に暴露す
ると共に、第２感温抵抗素子を密閉状態にし、第１、第
２感温抵抗素子を略同一温度で少なくとも１００℃以上
に加熱される雰囲気中に置き、その雰囲気による第１、
第２感温抵抗素子の抵抗値変化を電圧変換して温湿度変
化を検出するように構成した温湿度検出回路であって、
第１と第２の感温抵抗素子を直列に接続し、さらに第１
感温抵抗素子に直列に接続した抵抗体と、第２感温抵抗
素子を定電圧駆動するとともに定電圧駆動された第２感
温抵抗素子に流れる同じ電流値で第１感温抵抗素子およ
び抵抗体を駆動する定電圧駆動回路とを備え、前記抵抗
体の両端電圧を検出し温度出力とすることを特徴とする
温湿度検出回路を提供するものである。Means for Solving the Problems The present invention provides the following 3
There are different kinds of inventions. A first invention includes first and second temperature-sensitive resistance elements, exposing the first temperature-sensitive resistance element to an atmosphere, and closing the second temperature-sensitive resistance element to form a first and second temperature-sensitive resistance element. The resistance element is placed in an atmosphere heated to at least 100 ° C. or more at substantially the same temperature, and the first,
A temperature / humidity detection circuit configured to detect a temperature / humidity change by converting a resistance value change of a second temperature-sensitive resistance element into a voltage,
First and second temperature-sensitive resistance elements are connected in series, and
A resistor connected in series with the temperature sensitive resistive element, a first temperature sensitive resistor element and the resistor with the same current flowing through the second temperature sensitive resistor element to a second temperature sensitive resistor element constant voltage drive with a constant voltage drive and a constant voltage drive circuit for driving the body, there is provided a temperature and humidity detecting circuit, characterized in that the detected temperature output voltage across the resistor.
【０００７】第２の発明は、第１および第２感温抵抗素
子を具備し、第１感温抵抗素子を雰囲気に暴露すると共
に、第２感温抵抗素子を密閉状態にし、第１、第２感温
抵抗素子を略同一温度で少なくとも１００℃以上に加熱
される雰囲気中に置き、その雰囲気による第１、第２感
温抵抗素子の抵抗値変化を電圧変換して温湿度変化を検
出するように構成した温湿度検出回路であって、第１と
第２の感温抵抗素子を直列に接続し、さらに第２感温抵
抗素子に直列に接続した電流設定用の抵抗体と、この抵
抗体に並列に接続したスイッチング素子と、第２感温抵
抗素子および抵抗体を定電圧駆動するとともに定電圧駆
動された第２感温抵抗素子および抵抗体に流れる同じ電
流値で第１感温抵抗素子を駆動する定電圧駆動回路とを
備え、湿度検出時には前記スイッチング素子をオンと
し、温度検出時には前記スイッチング素子をオフとして
切り替えることを特徴とする温湿度検出回路を提供する
ものである。According to a second aspect of the present invention, the first and second temperature-sensitive resistance elements are provided, and the first and second temperature-sensitive resistance elements are exposed to an atmosphere, and the second temperature-sensitive resistance element is sealed. The two temperature-sensitive resistance elements are placed in an atmosphere heated to at least 100 ° C. or more at substantially the same temperature, and a change in the resistance value of the first and second temperature-sensitive resistance elements due to the atmosphere is converted into a voltage to detect a change in temperature and humidity. A temperature-humidity detecting circuit configured as described above, wherein a first and second temperature-sensitive resistance elements are connected in series, and a current setting resistor connected in series to the second temperature-sensitive resistance element; a switching element connected in parallel to the body, a first temperature sensitive resistor with the same current flowing through the second temperature sensitive resistor element and the resistor to the second temperature sensitive resistor element and the resistor is constant voltage drive with a constant voltage drive and a constant voltage drive circuit for driving the device, when the humidity detected And ON the switching element
And, at the time of temperature detection is to provide a temperature and humidity detecting circuits and switches <br/> the switching element as an off.
【０００８】第３の発明は、第１および第２感温抵抗素
子を具備し、第１感温抵抗素子を雰囲気に暴露すると共
に、第２感温抵抗素子を密閉状態にし、第１、第２感温
抵抗素子を略同一温度で少なくとも１００℃以上に加熱
される雰囲気中に置き、その雰囲気による第１、第２感
温抵抗素子の抵抗値変化を電圧変換して温湿度変化を検
出するように構成した温湿度検出回路であって、第１感
温抵抗素子に第２感温抵抗素子を直列に接続し、さらに
第２感温抵抗素子に並列に接続した電流設定用の抵抗体
と、第２感温抵抗素子または抵抗体を定電圧駆動すると
ともに第２感温抵抗素子または抵抗体に流れる同じ電流
値で第１感温抵抗素子を駆動する定電圧駆動回路と、第
２感温抵抗素子か抵抗体を定電圧駆動するかを切り替え
るスイッチング素子とを備え、前記スイッチング素子に
より、湿度検出時には前記第２感温抵抗体素子を定電圧
駆動し、温度検出時には前記抵抗体を定電圧駆動するよ
うに切り替えることを特徴とする温湿度検出回路を提供
するものである。According to a third aspect of the present invention, there are provided first and second temperature-sensitive resistance elements. The first and second temperature-sensitive resistance elements are exposed to an atmosphere, and the second temperature-sensitive resistance element is sealed. The two temperature-sensitive resistance elements are placed in an atmosphere heated to at least 100 ° C. or more at substantially the same temperature, and a change in the resistance value of the first and second temperature-sensitive resistance elements due to the atmosphere is converted into a voltage to detect a change in temperature and humidity. A temperature-humidity detecting circuit configured as described above, wherein a second temperature-sensitive resistor is connected in series to the first temperature-sensitive resistor, and a current setting resistor connected in parallel to the second temperature-sensitive resistor.
When the second temperature-sensitive resistor or resistor is driven at a constant voltage ,
The same current both flowing through the second temperature-sensitive resistance element or resistor
Includes a constant voltage drive circuit for driving the first temperature sensitive resistor element with a value, and switching elements of the second temperature sensitive resistance element or resistor switching between the constant voltage driving, by the switching element, wherein at the time of the humidity detecting the (2) The temperature- sensitive resistor element is driven at a constant voltage, and when the temperature is detected, the resistor is driven at a constant voltage.
The temperature and humidity detection circuit is characterized in that switching is performed in the following manner.
【０００９】前記スイッチング素子により温度出力に切
り替える際に、電流設定用の抵抗体の抵抗値は、第１感
温抵抗素子が湿度に対しては抵抗値変化を示すことが無
い自己加熱温度以下になる通電電流値に設定するように
構成されることが好ましい。When switching to the temperature output by the switching element, the resistance value of the current setting resistor is set to be equal to or lower than the self-heating temperature at which the first temperature-sensitive resistance element does not show a change in resistance value against humidity. It is preferable that the configuration is such that the current value is set as follows.
【００１０】[0010]
【作用】第１の発明によれば、第２感温抵抗素子の抵抗
値は雰囲気温度で決定されるが通電電流値は第２感温抵
抗素子の抵抗値と印加電圧で決定されるため、この通電
電流値を第１感温抵抗素子に接続された抵抗体で検出す
ることで温度出力を得ることができる。According to the first aspect of the invention, the resistance value of the second temperature-sensitive resistor is determined by the ambient temperature, but the current value is determined by the resistance value of the second temperature-sensitive resistor and the applied voltage. A temperature output can be obtained by detecting this energizing current value with a resistor connected to the first temperature-sensitive resistance element.
【００１１】第２の発明によれば、温度検出時は、第
１、第２感温抵抗素子の通電電流値が小さく設定される
ので、自己加熱温度が下がり、第１感温抵抗素子は湿度
の影響による抵抗値変化を示さなくなる。よって、出力
電圧は第１感温抵抗素子の抵抗値と第２感温抵抗素子の
抵抗値と直列に接続された抵抗値との合算値との比を示
すこととなり、温度変化による抵抗比の変化を電圧変換
により温度出力を得ることができる。According to the second aspect of the present invention, when the temperature is detected, the current values of the first and second temperature-sensitive resistance elements are set to be small. No change in resistance value due to the influence of. Therefore, the output voltage indicates the ratio of the resistance value of the first temperature-sensitive resistance element to the sum of the resistance value of the second temperature-sensitive resistance element and the resistance value connected in series. The temperature output can be obtained by converting the change into a voltage.
【００１２】第３の発明によれば、温度検出時は、第１
感温抵抗素子の通電電流値が小さく設定されるので、自
己加熱温度が下がり、第１感温抵抗素子は湿度の影響に
よる抵抗値変化を示さなくなる。よって、出力電圧は第
１感温抵抗素子の抵抗値と、抵抗体の抵抗値との比を示
すこととなり、温度変化による抵抗比の変化を電圧変換
により温度出力を得ることができる。According to the third aspect, when the temperature is detected, the first
Since the current value of the temperature-sensitive resistance element is set to be small, the self-heating temperature decreases, and the first temperature-sensitive resistance element does not show a resistance value change due to the influence of humidity. Therefore, the output voltage indicates the ratio of the resistance value of the first temperature-sensitive resistance element to the resistance value of the resistor, and a temperature output can be obtained by converting the change in the resistance ratio due to the temperature change into a voltage.
【００１３】[0013]
【実施例】以下、図面に示す３種類の実施例を用いて本
発明を詳述する。なお、これによって本発明が限定され
るものでない。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to three embodiments shown in the drawings. Note that the present invention is not limited by this.
【００１４】図１は本発明による実施例１の温湿度検出
回路である。図１において、Ｒsは湿気を含む雰囲気に
暴露され湿度変化を検出する第１感温抵抗素子、Ｒrは
その雰囲気の温度変化を検出する第２感温抵抗素子、Ａ
1はオペアンプ、Ｒ1、Ｒ2 Ｒ6は固定抵抗、Ｅvはこの温
湿度検出回路に供給される直流定電圧である。また、Ｅ
oはＲ1とＲ2で決定される基準電圧でありオペアンプＡ1
で定電圧駆動回路を構成している。FIG. 1 shows a temperature and humidity detecting circuit according to a first embodiment of the present invention. In FIG. 1, Rs is a first resistance element for detecting a change in humidity when exposed to an atmosphere containing moisture, Rr is a second resistance element for detecting a change in temperature of the atmosphere, A
1 is an operational amplifier, R 1 , R 2 and R 6 are fixed resistors, and Ev is a DC constant voltage supplied to the temperature / humidity detecting circuit. Also, E
o is a reference voltage determined by R 1 and R 2 , and the operational amplifier A 1
Constitute a constant voltage drive circuit.
【００１５】Ｉo（＝Ｅo/Ｒr）は固定抵抗Ｒ6 、第１感
温抵抗素子Ｒs 、第２感温抵抗素子Ｒrに流れる電流値
である。この時の湿度検知出力ＶAHは次式で示される。 ＶAH＝Ｖ1＝(１＋Ｒs/Ｒr)×Ｅo また、この時の温度検知出力ＶTは次式で示され、固定
抵抗（Ｒ6）の両端電圧ＶTを検知している。 ＶT＝Ｖ2−Ｖ1＝｛１＋( Ｒs ＋Ｒ6)/ Ｒr ｝×Ｅo −
( １＋Ｒs/Ｒr)×Ｅo＝(Ｒ6/Ｒr)×Ｅo 即ち、湿度検知出力はＲs/Ｒrの比を、温度検知出力は
Ｒ6/Ｒrの比をそれぞれ電圧変換していることになる。Io (= Eo / Rr) is a current value flowing through the fixed resistor R 6 , the first temperature-sensitive resistor Rs, and the second temperature-sensitive resistor Rr. The humidity detection output V AH at this time is expressed by the following equation. V AH = V 1 = (1 + Rs / Rr) × Eo The temperature detection output V T at this time is represented by the following formula, which detects a fixed voltage across V T of the resistor (R 6). V T = V 2 -V 1 = {1+ (Rs + R 6) / Rr} × Eo -
(1 + Rs / Rr) × Eo = (R 6 / Rr) × Eo i.e., humidity detection output ratio of Rs / Rr, so that the temperature detection output are respectively voltage conversion ratio of R 6 / Rr.
【００１６】図２は第１、第２感温抵抗素子に用いられ
る白金抵抗の温度−抵抗値特性を示す説明図である。図
２に示すように、白金抵抗は正の温度係数を持つために
図２に示すような特性を示す。FIG. 2 is an explanatory diagram showing temperature-resistance characteristics of platinum resistors used in the first and second temperature-sensitive resistance elements. As shown in FIG. 2, the platinum resistor has a positive temperature coefficient and thus exhibits the characteristics shown in FIG.
【００１７】以下、図１に基づいて検出原理を説明す
る。通常湿度検知時は２００〜４００°Ｃ程度に自己加
熱するように電流値は設定される。即ちＲrの両端電圧
は上記温度に設定されるような抵抗値になるようにＩo
＝Ｅo/Ｒrで設定される電流値で駆動される。この場合
でも第１、第２の感温抵抗素子は雰囲気の温度変化に対
して抵抗値を同一の変化率で変化させる。Hereinafter, the principle of detection will be described with reference to FIG. At the time of normal humidity detection, the current value is set so as to self-heat to about 200 to 400 ° C. That is, Io is set so that the voltage across Rr becomes a resistance value set at the above temperature.
= Eo / Rr. Even in this case, the first and second temperature-sensitive resistance elements change their resistance values at the same rate of change with respect to the temperature change of the atmosphere.
【００１８】一方湿度変化が生じると湿度の状態に応じ
て第１感温抵抗素子のみが抵抗値を変化させるためにＲ
s/Ｒrの比に変化が生じ湿度に応じた出力変化が発生す
る。一方当該回路における通電電流値はＥo/Ｒrで決定
される。即ち温度が変化したとき第２の感温抵抗素子の
抵抗値はその変化に応じて変動するがそれに従い通電電
流値も変化する。従って、その通電電流値の変化を抵抗
Ｒ6の両端電圧の変化として検出すれば温度検出ができ
る。On the other hand, when a change in humidity occurs, only the first temperature-sensitive resistance element changes the resistance value according to the state of humidity.
The ratio of s / Rr changes, and the output changes according to the humidity. On the other hand, the current value in the circuit is determined by Eo / Rr. That is, when the temperature changes, the resistance value of the second temperature-sensitive resistance element changes according to the change, and the current value changes accordingly. Therefore, the temperature can be detected by detecting the change in the electric current value as a change in voltage across the resistor R 6.
【００１９】図３は本発明による実施例２の温湿度検出
回路である。図３において、Ｒsは湿気を含む雰囲気に
暴露され湿度変化を検出する第１感温抵抗素子、Ｒrは
その雰囲気の温度変化を検出する第２感温抵抗素子、Ａ
1、Ａ2はオペアンプ、Ｒ1〜Ｒ3、Ｒ40、Ｒ41、Ｒ60は固
定抵抗、Ｓ1、Ｓ2はスイッチ（スイッチング素子）であ
る。Ｅvはこの温湿度検出回路に供給される直流定電圧
である。また、ＥoはＲ1とＲ2で決定される基準電圧で
ありオペアンプＡ1で定電圧・定電流回路を構成してい
る。また、Ｉo（＝Ｅo/（Ｒr ＋Ｒ60) ）は第１感温抵
抗素子Ｒs 、第２感温抵抗素子Ｒr 、固定抵抗Ｒ60（電
流設定用の抵抗）に流れる電流値である。なお、Ｒs 、
Ｒr には正の温度係数の白金抵抗が用いられる。FIG. 3 shows a temperature and humidity detecting circuit according to a second embodiment of the present invention. In FIG. 3, Rs is a first temperature-sensitive resistance element that detects a change in humidity when exposed to an atmosphere containing moisture, Rr is a second temperature-sensitive resistance element that detects a temperature change in the atmosphere, A
1 and A 2 are operational amplifiers, R 1 to R 3 , R 40 , R 41 and R 60 are fixed resistors, and S 1 and S 2 are switches (switching elements). Ev is a DC constant voltage supplied to the temperature and humidity detection circuit. Further, Eo constitute a constant voltage and constant current circuit in the operational amplifier A 1 is a reference voltage determined by R 1 and R 2. Furthermore, Io (= Eo / (Rr + R 60)) is a current value flowing first temperature sensitive resistor element Rs, second temperature sensitive resistor element Rr, the fixed resistor R 60 (resistance of the current setting). Note that Rs,
A platinum resistance having a positive temperature coefficient is used for Rr.
【００２０】図３の（１）はスイッチＳ1、Ｓ2がオンさ
れた湿度検出時の状態を示す。従って、この時の湿度検
知出力ＶAHは次式で示される。 ＶAH＝Ｖout ＝−(Ｒs/Ｒr)×(Ｒ5/Ｒ3)×Ｅo ＋(１＋
Ｒ5/Ｚ4)×Ｅo 但し Ｚ4 ＝Ｒ40×Ｒ41/(Ｒ40＋Ｒ41) 図３の（２）はスイッチＳ1、Ｓ2がオフされた温度検知
時の状態を示す。従って、この時の温度検知出力ＶTは次
式で示される。 ＶT ＝Ｖout ＝−｛Ｒs/( Ｒr ＋Ｒ60)｝×(Ｒ5/Ｒ3)×
Ｅo＋(１＋Ｒ5/Ｒ4)×ＥoFIG. 3A shows a state when the switches S 1 and S 2 are turned on and humidity is detected. Therefore, the humidity detection output V AH at this time is expressed by the following equation. V AH = Vout = - (Rs / Rr) × (R 5 / R 3) × Eo + (1+
R 5 / Z 4 ) × Eo where Z 4 = R 40 × R 41 / (R 40 + R 41 ) FIG. 3B shows the state at the time of temperature detection when the switches S 1 and S 2 are turned off. Accordingly, the temperature detection output V T at this time is represented by the following formula. V T = Vout = - {Rs / (Rr + R 60)} × (R 5 / R 3) ×
Eo + (1 + R 5 / R 4 ) × Eo
【００２１】即ち、湿度検知時はＲs/Ｒrの比を、温度
検知時はＲs/(Ｒr ＋Ｒ60)の比をそれぞれ電圧変換して
いることになる。尚、Ｚ4の値は湿度検知時、温度検知
時それぞれの比に応じたＲ3/Ｚ4になるようにＲ41の切
り替えで設定される。That is, when humidity is detected, the ratio of Rs / Rr is converted, and when temperature is detected, the ratio of Rs / (Rr + R 60 ) is converted. The value of Z 4 when the humidity detecting, set by switching of the R 41 to be R 3 / Z 4 in accordance with the respective ratios during temperature detection.
【００２２】図４は第１、第２感温抵抗素子に用いられ
る白金抵抗の電流−電圧特性を示す説明図である。白金
抵抗は正の温度係数を持つために図４に示すような特性
を示す。FIG. 4 is an explanatory diagram showing current-voltage characteristics of platinum resistors used for the first and second temperature-sensitive resistance elements. Since the platinum resistance has a positive temperature coefficient, it exhibits characteristics as shown in FIG.
【００２３】以下、図３に基づいて検出原理を説明す
る。即ち印加電流（電圧）が小さいと抵抗値は小さく自
己加熱温度も低い。一方印加電流（電圧）が大きいと抵
抗値は大きく自己加熱温度が高くなる。通常湿度検知時
は２００〜４００°Ｃ程度に自己加熱するように電流値
は設定される。即ち、Ｒrの両端電圧は上記温度に設定
されるような抵抗値になるようにＩo＝Ｅo/Ｒrで設定さ
れる電流値で駆動される。Hereinafter, the principle of detection will be described with reference to FIG. That is, when the applied current (voltage) is small, the resistance value is small and the self-heating temperature is low. On the other hand, when the applied current (voltage) is large, the resistance value is large and the self-heating temperature is high. At the time of normal humidity detection, the current value is set so as to self-heat to about 200 to 400 ° C. That is, the voltage across Rr is driven with a current value set by Io = Eo / Rr such that the resistance value is set to the above-mentioned temperature.
【００２４】この場合でも第１、第２の感温抵抗素子は
雰囲気の温度変化に対して抵抗値を同一感温抵抗素子の
みが抵抗値を変化させるためＲs/Ｒrの比に変化が生じ
湿度に応じた出力変化が発生する。一方温度検出時は同
様のＥoに対して第２の感温抵抗素子に直列に接続され
たＲ 60 の合成抵抗値で設定される電流値Ｉo＝Ｅo/(Ｒr
＋Ｒ60）で駆動されることになる。Even in this case, the first and second temperature-sensitive resistance elements have the same resistance value with respect to a change in ambient temperature, and only the same temperature-sensitive resistance element changes the resistance value. An output change occurs according to. On the other hand the current value Io at the temperature detection is set by the combined resistance value of R 60 which are connected in series to the second thermo-sensitive resistance elements for similar Eo = Eo / (Rr
+ R 60 ).
【００２５】この時Ｒ60の値は感温抵抗体が湿度に対し
ては抵抗値変化を生じない自己加熱温度になる電流値に
なるように設定される。この場合でも第１、第２の感温
抵抗素子は温度変化に対して同様の変化率を示すが、第
２の感温抵抗素子にはＲ60が直列に接続されるためにＲ
s/(Ｒr＋Ｒ60)の比は温度によって異なることなり、従
って温度変化により出力が変化するので、この出力変化
より温度検知が可能となる。The value of this time R 60 is set to be the current value becomes self-heating temperature thermo-sensitive resistor does not produce a change in resistance against humidity. First In this case, the second temperature sensitive resistor element exhibits a similar change rate with respect to temperature changes, the second temperature sensitive resistor element R to R 60 are connected in series
Since the ratio of s / (Rr + R 60 ) varies depending on the temperature, and the output changes according to the temperature change, the temperature can be detected from the output change.
【００２６】図５は本発明による実施例３の温湿度検出
回路である。図５において、Ｒsは湿気を含む雰囲気に
暴露され湿度変化を検出する第１感温抵抗素子、Ｒrは
その雰囲気の温度変化を検出する第２感温抵抗素子、Ａ
1、Ａ2はオペアンプ、Ｒ1〜Ｒ3、Ｒ40、Ｒ41、Ｒ60は固
定抵抗、Ｓ2、Ｓ3はスイッチ（スイッチング素子）であ
る。Ｅvはこの温湿度検出回路に供給される直流定電圧
である。また、ＥoはＲ 1とＲ2で決定される基準電圧で
ありオペアンプＡ1で定電圧・定電流回路を構成してい
る。また、Ｉo（＝Ｅo/(Ｒr＋Ｒ60)）は第１感温抵抗素
子Ｒs、第２感温抵抗素子Ｒr、固定抵抗Ｒ60に流れる電
流値である。なお、Ｒs、Ｒrはの正の温度係数の白金抵
抗が用いられる。FIG. 5 shows temperature and humidity detection according to a third embodiment of the present invention.
Circuit. In FIG. 5, Rs is an atmosphere containing moisture.
The first temperature-sensitive resistance element that detects the change in humidity due to exposure, Rr
A second temperature-sensitive resistance element for detecting a temperature change of the atmosphere, A
1, ATwoIs an operational amplifier, R1~ RThree, R40, R41, R60Is solid
Constant resistance, STwo, SThreeIs a switch (switching element)
You. Ev is the DC constant voltage supplied to this temperature and humidity detection circuit.
It is. Eo is R 1And RTwoWith the reference voltage determined by
Operational amplifier A1Constitute a constant voltage / constant current circuit.
You. Also, Io (= Eo / (Rr + R60)) Is the first temperature-sensitive resistor
Child Rs, second temperature-sensitive resistance element Rr, fixed resistance R60Electricity flowing through
It is a streaming value. Note that Rs and Rr are platinum resistors having a positive temperature coefficient.
Anti is used.
【００２７】図５の（１）はスイッチＳ2がオン、スイ
ッチＳ3が第２感温度抵抗素子を通電した湿度検出時の
状態を示す。従って、この時の湿度検知出力ＶAHは次式
で示される。 ＶAH＝Ｖout ＝−(Ｒs/Ｒr)×(Ｒ5/Ｒ3)×Ｅo＋(１＋Ｒ
5/Ｚ4)×Ｅo 但し Ｚ4＝Ｒ40×Ｒ41/(Ｒ40＋Ｒ41) 図５の（２）はスイッチＳ2がオフ、スイッチＳ3が固定
抵抗Ｒ61を通電した温度検知時の状態を示す。 従って、
この時の温度検知出力ＶTは次式で示される。 ＶT ＝Ｖout ＝−(Ｒs/Ｒ61)×(Ｒ5/Ｒ3)×Ｅo＋(１＋
Ｒ5/Ｒ4)×ＥoFIG. 5A shows the state when the switch S 2 is turned on and the switch S 3 detects the humidity when the second temperature-sensitive resistance element is energized. Therefore, the humidity detection output V AH at this time is expressed by the following equation. V AH = Vout = - (Rs / Rr) × (R 5 / R 3) × Eo + (1 + R
5 / Z 4 ) × Eo where Z 4 = R 40 × R 41 / (R 40 + R 41 ) FIG. 5 (2) shows the temperature detection when the switch S 2 is off and the switch S 3 is energized through the fixed resistor R 61. The state of is shown. Therefore,
Temperature detection output V T at this time is represented by the following formula. V T = Vout = − (Rs / R 61 ) × (R 5 / R 3 ) × Eo + (1+
R 5 / R 4 ) × Eo
【００２８】即ち印加電流（電圧）が小さいと抵抗値は
小さく自己加熱温度も低い。一方印加電流（電圧）が大
きいと抵抗値は大きく自己加熱温度が高くなる。通常湿
度検知時は２００〜４００℃程度に自己加熱するように
電流値は設定される。即ちＲrの両端電圧は上記温度に
設定されるような抵抗値になるようにＩo＝Ｅo/Ｒrで設
定される電流値で駆動される。That is, when the applied current (voltage) is small, the resistance value is small and the self-heating temperature is low. On the other hand, when the applied current (voltage) is large, the resistance value is large and the self-heating temperature is high. At the time of normal humidity detection, the current value is set so as to self-heat to about 200 to 400 ° C. That is, the voltage across Rr is driven by a current value set by Io = Eo / Rr so that the resistance value is set to the above-mentioned temperature.
【００２９】この場合でも第１、第２の感温抵抗素子は
雰囲気の温度変化に対して抵抗値を同一の変化率で変化
させる。一方湿度変化が生じると湿度の状態に応じて第
１感温抵抗体のみが抵抗値を変化させるためにＲs/Ｒr
の比に変化が生じ湿度に応じた出力変化が発生する。一
方温度検出時は同様のＥoに対して固定抵抗Ｒ 61 で設定
される電流値Ｅo/Ｒ 61 で駆動されることになる。Even in this case, the resistance values of the first and second temperature-sensitive resistance elements change at the same rate of change with respect to the temperature change of the atmosphere. On the other hand, when the humidity changes, only the first temperature-sensitive resistor changes the resistance value according to the humidity state, so that Rs / Rr
And the output changes according to the humidity. While the temperature detection time will be driven at a current value Eo / R 61 that is set by the fixed resistor R 61 for similar Eo.
【００３０】この時Ｒ 61 の値は感温抵抗体が湿度に対し
ては抵抗値変化を生じない自己加熱温度になる電流値に
なるように設定される。この場合でも第１感温抵抗素子
は温度変化に対して同様の変化率を示すが、電流設定用
の固定抵抗Ｒ 61 は固定値のためＲs/Ｒ 61 の比は温度によ
って異なることになり温度変化により出力が変化するこ
とになり、この出力変化より温度検知が可能となる。The value of this time R 61 is set to be the current value becomes self-heating temperature thermo-sensitive resistor does not produce a change in resistance against humidity. The first temperature sensitive resistor element even when the shows a similar change rate with respect to temperature changes, the fixed resistor R 61 for current setting ratio Rs / R 61 for a fixed value will be depend on the temperature the temperature The output changes due to the change, and the temperature can be detected from the output change.
【００３１】[0031]
【発明の効果】本発明によれば温度検知用の専用の装置
を用いることなく温湿度の検出が可能になる。According to the present invention, temperature and humidity can be detected without using a dedicated device for detecting temperature.
【図１】本発明による実施例１の温湿度検出回路であ
る。FIG. 1 is a temperature and humidity detection circuit according to a first embodiment of the present invention.
【図２】第１、第２感温抵抗素子に用いられる白金抵抗
の温度−抵抗値特性を示す説明図である。FIG. 2 is an explanatory diagram showing temperature-resistance characteristics of platinum resistors used for first and second temperature-sensitive resistance elements.
【図３】本発明による実施例２の温湿度検出回路であ
る。FIG. 3 is a temperature and humidity detection circuit according to a second embodiment of the present invention.
【図４】第１、第２感温抵抗素子に用いられる白金抵抗
の電流−電圧特性を示す説明図である。FIG. 4 is an explanatory diagram showing current-voltage characteristics of platinum resistors used for first and second temperature-sensitive resistance elements.
【図５】本発明による実施例３の温湿度検出回路であ
る。FIG. 5 is a temperature and humidity detection circuit according to a third embodiment of the present invention.
【図６】従来例１の湿度検出回路である。FIG. 6 is a humidity detection circuit of Conventional Example 1.
【図７】従来例２の湿度検出回路である。FIG. 7 is a humidity detection circuit of Conventional Example 2.
Ｒ1 固定抵抗 Ｒ2 固定抵抗 Ｒ3 固定抵抗 Ｒ4 固定抵抗 Ｒ5 固定抵抗 Ｒ6 固定抵抗 Ｒ40 固定抵抗 Ｒ41 固定抵抗 Ｒ60 固定抵抗 Ｒ61 固定抵抗 Ｒs 感温抵抗素子 Ｒr 感温抵抗素子 Ａ1 オペアンプ Ａ2 オペアンプ Ｓ1 スイッチ Ｓ2 スイッチ Ｓ3 スイッチR 1 fixed resistor R 2 fixed resistor R 3 fixed resistor R 4 fixed resistor R 5 fixed resistor R 6 fixed resistor R 40 fixed resistor R 41 fixed resistor R 60 fixed resistor R 61 fixed resistor Rs temperature sensitive resistive element Rr temperature sensitive resistive element A 1 operational amplifier A 2 op-amp S 1 switch S 2 switch S 3 switch
Claims (4)
第１感温抵抗素子を雰囲気に暴露すると共に、第２感温
抵抗素子を密閉状態にし、第１、第２感温抵抗素子を略
同一温度で少なくとも１００℃以上に加熱される雰囲気
中に置き、その雰囲気による第１、第２感温抵抗素子の
抵抗値変化を電圧変換して温湿度変化を検出するように
構成した温湿度検出回路であって、第１と第２の感温抵
抗素子を直列に接続し、さらに第１感温抵抗素子に直列
に接続した抵抗体と、第２感温抵抗素子を定電圧駆動す
るとともに定電圧駆動された第２感温抵抗素子に流れる
同じ電流値で第１感温抵抗素子および抵抗体を駆動する
定電圧駆動回路とを備え、前記抵抗体の両端電圧を検出
し温度出力とすることを特徴とする温湿度検出回路。And a first temperature-sensitive resistance element.
The first temperature-sensitive resistor is exposed to the atmosphere, the second temperature-sensitive resistor is sealed, and the first and second temperature-sensitive resistors are placed in an atmosphere heated to at least 100 ° C. at substantially the same temperature. A temperature-humidity detecting circuit configured to detect a temperature-humidity change by converting a resistance value change of the first and second temperature-sensitive resistance elements due to the atmosphere into a voltage, and comprising a first and a second temperature-sensitive resistance element. were connected in series, further a resistor connected in series to the first temperature sensitive resistor element, constant voltage driven the same current flowing through the second temperature sensitive resistive element with a second temperature sensitive resistive element to a constant voltage drive in a constant-voltage drive circuit for driving the first temperature sensitive resistor element and the resistor, the temperature and humidity detecting circuit, characterized in that the detected temperature output voltage across the resistor.
第１感温抵抗素子を雰囲気に暴露すると共に、第２感温
抵抗素子を密閉状態にし、第１、第２感温抵抗素子を略
同一温度で少なくとも１００℃以上に加熱される雰囲気
中に置き、その雰囲気による第１、第２感温抵抗素子の
抵抗値変化を電圧変換して温湿度変化を検出するように
構成した温湿度検出回路であって、第１と第２の感温抵
抗素子を直列に接続し、さらに第２感温抵抗素子に直列
に接続した電流設定用の抵抗体と、この抵抗体に並列に
接続したスイッチング素子と、第２感温抵抗素子および
抵抗体を定電圧駆動するとともに定電圧駆動された第２
感温抵抗素子および抵抗体に流れる同じ電流値で第１感
温抵抗素子を駆動する定電圧駆動回路とを備え、湿度検
出時には前記スイッチング素子をオンとし、温度検出時
には前記スイッチング素子をオフとして切り替えること
を特徴とする温湿度検出回路。2. It comprises first and second temperature-sensitive resistance elements,
The first temperature-sensitive resistor is exposed to the atmosphere, the second temperature-sensitive resistor is sealed, and the first and second temperature-sensitive resistors are placed in an atmosphere heated to at least 100 ° C. at substantially the same temperature. A temperature-humidity detecting circuit configured to detect a temperature-humidity change by converting a resistance value change of the first and second temperature-sensitive resistance elements due to the atmosphere into a voltage, and comprising a first and a second temperature-sensitive resistance element. Are connected in series, and furthermore, a current setting resistor connected in series to the second temperature-sensitive resistor, a switching element connected in parallel to this resistor, and a constant voltage connected to the second temperature-sensitive resistor and the resistor. Driven and constant voltage driven second
And a constant voltage drive circuit for driving the first temperature sensitive resistor element at the same current value flowing through the temperature sensing resistor element and the resistor, humidity test
When the temperature is detected, the switching element is turned on.
Temperature and humidity detecting circuit, characterized in that switching the switching element as an off to.
第１感温抵抗素子を雰囲気に暴露すると共に、第２感温
抵抗素子を密閉状態にし、第１、第２感温抵抗素子を略
同一温度で少なくとも１００℃以上に加熱される雰囲気
中に置き、その雰囲気による第１、第２感温抵抗素子の
抵抗値変化を電圧変換して温湿度変化を検出するように
構成した温湿度検出回路であって、第１感温抵抗素子に
第２感温抵抗素子を直列に接続し、さらに第２感温抵抗
素子に並列に接続した電流設定用の抵抗体と、第２感温
抵抗素子または抵抗体を定電圧駆動するとともに第２感
温抵抗素子または抵抗体に流れる同じ電流値で第１感温
抵抗素子を駆動する定電圧駆動回路と、第２感温抵抗素
子か抵抗体を定電圧駆動するかを切り替えるスイッチン
グ素子とを備え、前記スイッチング素子により、湿度検
出時には前記第２感温抵抗体素子を定電圧駆動し、温度
検出時には前記抵抗体を定電圧駆動するように切り替え
ることを特徴とする温湿度検出回路。3. It comprises first and second temperature-sensitive resistance elements,
The first temperature-sensitive resistor is exposed to the atmosphere, the second temperature-sensitive resistor is sealed, and the first and second temperature-sensitive resistors are placed in an atmosphere heated to at least 100 ° C. at substantially the same temperature. A temperature / humidity detecting circuit configured to detect a temperature / humidity change by converting a resistance value change of the first and second temperature-sensitive resistance elements due to the atmosphere into a voltage. the temperature resistance element connected in series, further a resistor for current setting is connected in parallel to a second temperature sensitive resistor element, the second sense with the second temperature sensitive resistive element or resistor to a constant voltage drive
The first temperature sensing with the same current value flowing through the temperature resistance element or resistor
It includes a constant voltage drive circuit for driving the resistive element, and switching elements of the second temperature sensitive resistance element or resistor switching between the constant voltage driving, by the switching element, the humidity test
At the time of output, the second temperature-sensitive resistor element is driven at a constant voltage ,
A temperature / humidity detection circuit that switches the resistor so as to be driven at a constant voltage upon detection.
切り替える際に、電流設定用の抵抗体の抵抗値は、第一
感温抵抗素子が湿度に対しては抵抗値変化を示すことが
無い自己加熱温度以下になる通電電流値に設定すること
を特徴とした請求項３記載の温湿度検出回路。4. When the switching element switches to temperature output, the resistance value of the current setting resistor is set to a self-heating temperature at which the first temperature-sensitive resistance element does not show a resistance value change with respect to humidity. 4. The temperature / humidity detecting circuit according to claim 3, wherein the current value is set to the following value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22888792A JP2885581B2 (en) | 1992-08-27 | 1992-08-27 | Temperature and humidity detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22888792A JP2885581B2 (en) | 1992-08-27 | 1992-08-27 | Temperature and humidity detection circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0674929A JPH0674929A (en) | 1994-03-18 |
| JP2885581B2 true JP2885581B2 (en) | 1999-04-26 |
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|---|---|---|---|
| JP22888792A Expired - Fee Related JP2885581B2 (en) | 1992-08-27 | 1992-08-27 | Temperature and humidity detection circuit |
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| Publication number | Publication date |
|---|---|
| JPH0674929A (en) | 1994-03-18 |
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| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |