JPH0634772B2 - Electric water heater - Google Patents
Electric water heaterInfo
- Publication number
- JPH0634772B2 JPH0634772B2 JP60288418A JP28841885A JPH0634772B2 JP H0634772 B2 JPH0634772 B2 JP H0634772B2 JP 60288418 A JP60288418 A JP 60288418A JP 28841885 A JP28841885 A JP 28841885A JP H0634772 B2 JPH0634772 B2 JP H0634772B2
- Authority
- JP
- Japan
- Prior art keywords
- switching element
- circuit
- heater
- time
- temperature
- 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.)
- Expired - Lifetime
Links
Landscapes
- Cookers (AREA)
- Thermally Insulated Containers For Foods (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、調理物を沸騰させた後、一定温度に保つ電気
湯沸し器に関するものである。Description: TECHNICAL FIELD The present invention relates to an electric water heater that keeps a cooking product at a constant temperature after boiling.
従来の技術 従来の電気湯沸し器でお湯を沸かした後、保温する場
合、沸騰検知は蒸気を検知して行ない、保温は容器の温
度を検知して行なうなど、沸騰検知手段と保温手段がそ
れぞれ異なっていた。Conventional technology When boiling water with a conventional electric water heater and then keeping it warm, boiling is detected by detecting steam, and keeping temperature by detecting the temperature of the container. Was there.
発明が解決しようとする問題点 このような従来の電気湯沸し器では、沸騰検知手段と保
温手段がそれぞれ異なっているため、沸騰温度と保温温
度に相関がなく、したがって沸騰温度が気圧等の影響で
変化しても保温温度は一定であるため、気圧の低い所で
は、沸騰した後、保温に切替っても、保温温度よりも沸
騰温度が低いために保温時も沸騰を続けてしまうという
問題点を有していた。Problems to be Solved by the Invention In such a conventional electric water heater, since the boiling detection means and the heat retention means are different from each other, there is no correlation between the boiling temperature and the heat retention temperature, and therefore the boiling temperature is affected by atmospheric pressure or the like. Since the heat retention temperature is constant even if it changes, even if it switches to heat retention after boiling in a place with a low atmospheric pressure, the boiling temperature is lower than the heat retention temperature, so it continues to boil during heat retention. Had.
本発明はこのような問題点を解決した電気湯沸し器を提
供することを目的とする。An object of the present invention is to provide an electric water heater that solves such problems.
問題点を解決するための手段 上記問題点を解決するために本発明は、沸騰検知手段と
保温手段を同じ回路で行ない、所定温度を検出した時点
の充電時間計測手段の計時時間を基準として、前記計時
時間が前記基準より一定割合小さくなるときを沸騰時と
判断するとともに、沸騰温度からの相対温度で保温温度
を設定するようにしたものである。Means for Solving the Problems In order to solve the above problems, the present invention performs the boiling detection means and the heat retention means in the same circuit, based on the time measured by the charging time measuring means at the time of detecting the predetermined temperature, When the time measured is shorter than the reference by a certain percentage, it is determined that the time is boiling, and the heat retention temperature is set by the relative temperature from the boiling temperature.
作 用 上記構成によれば、沸騰温度に応じて保温温度も変化す
るため、気圧等の変化で沸騰温度が変化した場合におい
ても、保温温度は沸騰温度よりも常に一定温度だけ低い
温度に設定されるものである。Operation According to the above configuration, the heat retention temperature also changes according to the boiling temperature.Therefore, even when the boiling temperature changes due to changes in atmospheric pressure, etc., the heat retention temperature is always set lower than the boiling temperature by a certain temperature. It is something.
実施例 以下、本発明の一実施例を添付図面にもとづいて説明す
る。第１図において、１は商用電源、２はヒータ、３は
制御素子を構成するリレーで、リレー接点４とリレーコ
イル５により構成されている。６は温度を検知するサー
ミスタ７、抵抗８，９、第２のスイッチング素子を構成
するトランジスタ１０および第３のスイッチング素子を
構成するトランジスタ１１よりなる分圧回路、１２は抵
抗１３，１４、コンデンサ１５および第１のスイッチン
グ素子を構成するトランジスタ１６よりなる充電回路、
１７は比較回路を構成するコンパレータで、このコンパ
レータ１７は前記充電回路１２のコンデンサ電位と分圧
回路６の分圧電位を比較する。１８は充電時間計測手
段、１９は制御手段である。第２図はａ点とｂ点の波形
を示したものである。Embodiment One embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, 1 is a commercial power source, 2 is a heater, 3 is a relay that constitutes a control element, and is constituted by a relay contact 4 and a relay coil 5. Reference numeral 6 is a thermistor 7 for detecting temperature, resistors 8 and 9, a voltage dividing circuit including a transistor 10 forming a second switching element and a transistor 11 forming a third switching element, and 12 is resistors 13 and 14 and a capacitor 15 And a charging circuit including a transistor 16 that constitutes the first switching element,
Reference numeral 17 is a comparator that constitutes a comparison circuit, and this comparator 17 compares the capacitor potential of the charging circuit 12 with the divided potential of the voltage dividing circuit 6. Reference numeral 18 is a charging time measuring means, and 19 is a control means. FIG. 2 shows the waveforms at points a and b.
上記構成において、次にその動作を説明する。サーミス
タクの抵抗値Ｒ７，抵抗８，９，１３，１４の抵抗値を
それぞれＲ８，Ｒ９，Ｒ13，Ｒ14、直流電圧をＶｃとす
れば、トランジスタ１０とトランジスタ１６がＯＮして
いるときは、ａ点の電位 ｂ点の電位 となる。Next, the operation of the above configuration will be described. If the resistance value R 7 of the thermistor, the resistance values of the resistors 8 , 9 , 13 , 14 are R 8 , R 9 , R 13 , R 14 , respectively, and the DC voltage is V c , the transistor 10 and the transistor 16 are turned on. The potential at point a potential at point b Becomes
そしてトランジスタ１０とトランジスタ１６がＯＮして
いるとき、サーミスタ７の温度が７０℃でＶａ＝Ｖｂと
なるようにＲ８，Ｒ13，Ｒ14を設定すれば、サーミスタ
７の温度が７０℃以下のときは、Ｖａ≦Ｖｂとなり、そ
の結果、コンパレータ１７の出力は常にＬＯＷである。
この状態では、制御手段１９はリレーコイル５に通電し
てリレー接点４を短絡しているため、ヒータ２は発熱す
る。このヒータ２の発熱により、容器が熱せられてサー
ミスタ７の温度が上昇し、そして７０℃を越えれば、Ｖ
ａ＞Ｖｂとなり、その結果、コンパレータ１７の出力が
ＨＩＧＨになる。このとき、制御手段１９がトランジス
タ１６にＯＦＦ信号を出力すれば、トランジスタ１６は
ＯＦＦとなりその結果、抵抗１３を介してコンデンサ１
５が充電される。この充電によりＶｂ＝Ｖａとなれば、
コンパレータ１７の出力はＬＯＷとなり、その結果、制
御手段１９によりトランジスタ１６がＯＮし、抵抗１４
を通じてコンデンサ１５の電荷を放電させる。一定時間
（ここでは１秒）毎にコンパレータ１７がＨＩＧＨとな
っている時間（充電時間）を充電時間計測手段１８が計
測することにより、７０℃直後の１秒間当りの充電時間
の変化すなわち充電時間の変化率がわかり、サーミスタ
７の温度変化が求められる。この変化を初期値とし、充
電時間の変化が初期値の１／ｎ（ここでは1/3）になれ
ば、サーミスタ７の温度が飽和点に達したことになり、
容器内の湯が沸いたことがわかる。これを沸騰時点とす
る。この時点での充電時間をＴとする。ここで、抵抗Ｒ
９を抵抗Ｒ８よりもサーミスタ温度に換算して５℃分だ
け低い抵抗値に設定しておき、沸騰時点以後はトランジ
スタ１０がＯＦＦし、かつトランジスタ１１がＯＮする
ようにする。そして、ヒータ２を通電制御して充電時間
がＴになるような抵抗値にサーミスタ７の温度を保つよ
うにすれば、サーミスタ７は、沸点−５℃に保たれる。Then, when the transistors 10 and 16 are turned on, if R 8 , R 13 and R 14 are set so that the temperature of the thermistor 7 is 70 ° C. and V a = V b , the temperature of the thermistor 7 is 70 ° C. In the following cases, V a ≦ V b , and as a result, the output of the comparator 17 is always LOW.
In this state, the control means 19 energizes the relay coil 5 to short-circuit the relay contact 4, so that the heater 2 generates heat. Due to the heat generated by the heater 2, the container is heated and the temperature of the thermistor 7 rises.
a > V b , and as a result, the output of the comparator 17 becomes HIGH. At this time, if the control means 19 outputs an OFF signal to the transistor 16, the transistor 16 is turned OFF, and as a result, the capacitor 1 is connected via the resistor 13.
5 is charged. If V b = V a by this charging,
The output of the comparator 17 becomes LOW, and as a result, the transistor 16 is turned on by the control means 19 and the resistor 14
The electric charge of the capacitor 15 is discharged through. The charging time measuring means 18 measures the time (charging time) during which the comparator 17 is HIGH for every fixed time (here, 1 second), so that the change in charging time per second immediately after 70 ° C., that is, the charging time. The temperature change of the thermistor 7 can be obtained by knowing the rate of change of. If this change is taken as the initial value and the change in charging time becomes 1 / n (1/3 here) of the initial value, it means that the temperature of the thermistor 7 has reached the saturation point,
You can see that the water in the container boiled. This is the boiling point. Let T be the charging time at this point. Where resistance R
9 is converted into a thermistor temperature lower than the resistance R 8 and set to a resistance value lower by 5 ° C. so that the transistor 10 is turned off and the transistor 11 is turned on after the boiling point. Then, by energizing the heater 2 to keep the temperature of the thermistor 7 at a resistance value such that the charging time becomes T, the thermistor 7 is kept at a boiling point of -5 ° C.
発明の効果 以上のように本発明によれば、沸騰温度に応じて保温温
度も変化するため、気圧等の変化で沸騰温度が変化した
場合でも、保温温度が沸騰温度を上回って沸騰を続ける
という問題点はなく、しかも沸騰温度に近い温度で保温
を行なうことができるものである。As described above, according to the present invention, since the heat retention temperature also changes according to the boiling temperature, even if the boiling temperature changes due to a change in atmospheric pressure or the like, the heat retention temperature exceeds the boiling temperature and continues boiling. There is no problem, and the heat can be kept at a temperature close to the boiling temperature.
また、充電回路のコンデンサ電位と分圧回路の分圧電位
とが一致するまではコンデンサへの充電時間の変化率を
検知しないので、ヒータへの通電開始直後の水温の温度
変化率が小さいときに、誤って沸騰と判断され保温動作
に移行することなく、正確に沸騰検知を行うことができ
る。Also, since the rate of change of the charging time to the capacitor is not detected until the capacitor potential of the charging circuit and the divided potential of the voltage dividing circuit match, when the rate of change of the water temperature immediately after the start of energizing the heater is small. It is possible to accurately detect boiling without erroneously determining boiling and shifting to the heat retaining operation.
第１図は本発明の一実施例を示す電気湯沸し器の回路
図、第２図は同回路における各部の波形図である。 ２……ヒータ、３……リレー（制御素子）、６……分圧
回路、７……サーミスタ、８，９，１３，１４……抵
抗、１０……トランジスタ（第２のスイッチング素
子）、１１……トランジスタ（第３のスイッチング素
子）、１２……充電回路、１５……コンデンサ、１６…
…トランジスタ（第１のスイッチング素子）、１７……
コンパレータ（比較回路）、１８……充電時間計測手
段、１９……制御手段。FIG. 1 is a circuit diagram of an electric water heater showing an embodiment of the present invention, and FIG. 2 is a waveform diagram of each part in the circuit. 2 ... Heater, 3 ... Relay (control element), 6 ... Voltage dividing circuit, 7 ... Thermistor, 8, 9, 13, 14 ... Resistor, 10 ... Transistor (second switching element), 11 ... Transistor (third switching element), 12 ... Charging circuit, 15 ... Capacitor, 16 ...
... Transistor (first switching element), 17 ...
Comparator (comparison circuit), 18 ... Charging time measuring means, 19 ... Control means.
Claims (1)
タの通電制御を行なう制御素子と、前記水の温度を検知
するサーミスタと、第１の抵抗と第１のスイッチング素
子を直列接続した直列回路と並列に接続されたコンデン
サと、このコンデンサに直列接続した第２の抵抗からな
る充電回路と、前記サーミスタに第３の抵抗と第２のス
イッチング素子の直列回路を直列に接続し、かつこの直
列回路に前記第３の抵抗より抵抗値の小さい第４の抵抗
と第３のスイッチング素子の直列回路を並列に接続して
構成した分圧回路と、前記充電回路のコンデンサ電位と
分圧回路の分圧電位を比較する比較回路と、前記コンデ
ンサ電位が前記分圧電位より小さい状態から前記コンデ
ンサ電位と前記分圧電位とが等しくなるまでの時間を計
測する充電時間計測手段と、前記比較回路の出力に基づ
いて、制御素子、第１，第２，第３のスイッチング素子
を制御する制御手段とからなり、前記制御手段は、前記
第１のスイッチング素子と前記第２のスイッチング素子
が閉じているときの前記充電時間計測手段の計時時間に
より所定温度を検出すると、その検出した時点の計時時
間を基準として、前記計時時間が前記基準より一定割合
小さくなるまでは前記制御素子を制御して前記ヒータへ
通電し、前記基準より一定割合小さくなる以後は、前記
第２のスイッチング素子を開きかつ前記第３のスイッチ
ング素子を閉じるとともに、前記ヒータを通電制御させ
て前記計時時間を前記基準より一定割合小さくなるとき
と同じにする電気湯沸し器。1. A heater for heating water in a container, a control element for controlling energization of the heater, a thermistor for detecting the temperature of the water, a first resistor and a first switching element are connected in series. A capacitor connected in parallel with the series circuit, a charging circuit composed of a second resistor connected in series with the capacitor, a series circuit of a third resistor and a second switching element connected in series to the thermistor, and A voltage dividing circuit configured by connecting a series circuit of a fourth resistor having a smaller resistance value than the third resistor and a third switching element in parallel to the series circuit, a capacitor potential of the charging circuit, and a voltage dividing circuit. And a charging time meter for measuring the time from the state where the capacitor potential is smaller than the divided potential until the capacitor potential and the divided potential become equal to each other. Means and control means for controlling the control element and the first, second, and third switching elements based on the output of the comparison circuit, wherein the control means comprises the first switching element and the second switching element. When the predetermined temperature is detected by the time measured by the charging time measuring means when the switching element is closed, the control is performed until the time measured becomes a certain percentage smaller than the reference, based on the time measured at the time of detection. After controlling the element to energize the heater and become smaller than the reference by a certain ratio, the second switching element is opened and the third switching element is closed, and the heater is energized to control the time count. An electric water heater that is the same as when the above is reduced by a certain ratio from the above standard.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60288418A JPH0634772B2 (en) | 1985-12-20 | 1985-12-20 | Electric water heater |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60288418A JPH0634772B2 (en) | 1985-12-20 | 1985-12-20 | Electric water heater |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62144614A JPS62144614A (en) | 1987-06-27 |
| JPH0634772B2 true JPH0634772B2 (en) | 1994-05-11 |
Family
ID=17729956
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60288418A Expired - Lifetime JPH0634772B2 (en) | 1985-12-20 | 1985-12-20 | Electric water heater |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0634772B2 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60212120A (en) * | 1984-04-09 | 1985-10-24 | 三洋電機株式会社 | Temperature controller of pot |
| JPS60234619A (en) * | 1984-05-07 | 1985-11-21 | 株式会社日立ホームテック | Temperature controller of electric pots |
-
1985
- 1985-12-20 JP JP60288418A patent/JPH0634772B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62144614A (en) | 1987-06-27 |
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