JPS6129117B2 - - Google Patents
Info
- Publication number
- JPS6129117B2 JPS6129117B2 JP55001091A JP109180A JPS6129117B2 JP S6129117 B2 JPS6129117 B2 JP S6129117B2 JP 55001091 A JP55001091 A JP 55001091A JP 109180 A JP109180 A JP 109180A JP S6129117 B2 JPS6129117 B2 JP S6129117B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- power
- input
- control circuit
- inverter circuit
- 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
Links
- 238000001514 detection method Methods 0.000 claims description 31
- 238000010438 heat treatment Methods 0.000 claims description 23
- 239000004065 semiconductor Substances 0.000 claims description 21
- 230000006698 induction Effects 0.000 claims description 14
- 230000010355 oscillation Effects 0.000 claims description 4
- 230000003321 amplification Effects 0.000 claims 1
- 238000003199 nucleic acid amplification method Methods 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 7
- 239000003990 capacitor Substances 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 230000007423 decrease Effects 0.000 description 3
- 238000003079 width control Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000010411 cooking Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
Landscapes
- Cookers (AREA)
Description
【発明の詳細な説明】
本発明は誘導加熱調理器に関するもので、特に
その小物検知装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an induction heating cooker, and particularly to a small object detection device thereof.
従来より誘導加熱調理器には、ナイフやスプー
ンなどの小物金属が加熱された場合、炎が見えな
いため誤まつて手に触れた場合にやけどの恐れが
あるので、小物金属は加熱しないような保護装置
すなわち、小物検知装置が装備されていた。従来
の方法として、例えばインバータ回路の入力電流
を小物設定レベルと比較したり、あるいは入力電
流を制御する場合には、小物設定レベルを、入力
電流設定レベルと連動させる方法などが考えられ
ていた。しかしながら、例えば、入力電力を
100Wから1200Wまで、インバータ回路のパワー
スイツチング半導体の導通期間あるいは周波数を
制御して連続的に制御する場合には、小物検知が
動作しない欠点があつた。すなわち、誘導加熱調
理器の入力電流が例えば、入力電圧100Vで2A、
よつて200Wとなるようにパワースイツチング半
導体の導通期間又は導通オンオフデユーテイを制
御した場合には、入力電流設定レベルに連動して
小物検知レベルを下げても、小物金属は2Aまで
入力電力が下がり、小物検知レベル以上の入力電
流となる。例えば、入力電流設定レベルを2A、
小物設定レベルをその半分の1Aと設定した場合
では、入力電流が2Aとなるように、フイードバ
ツク制御し、小物金属でも2Aに設定可能とな
り、入力設定レベルと入力検知レベルは等しくな
る。もし例えば、12Aに入力設定レベルをする
と、小物金属は、入力検知レベルが約半分の6A
となり、設定レベルに達しないので、小物と判断
できる。 Traditionally, induction heating cookers have been designed to prevent small metal items such as knives and spoons from being heated because the flame cannot be seen and there is a risk of burns if you accidentally touch them. It was equipped with a protective device, namely a small object detection device. Conventional methods include, for example, comparing the input current of an inverter circuit with an accessory setting level, or, when controlling the input current, linking the accessory setting level with the input current setting level. However, for example, if the input power
When continuously controlling the conduction period or frequency of the power switching semiconductor of the inverter circuit from 100W to 1200W, there was a drawback that the small object detection did not work. In other words, the input current of an induction heating cooker is, for example, 2A at an input voltage of 100V.
Therefore, if the conduction period or conduction on/off duty of the power switching semiconductor is controlled to be 200W, even if the small object detection level is lowered in conjunction with the input current setting level, the input power for small metal objects will be 2A. decreases, and the input current exceeds the small object detection level. For example, if the input current setting level is 2A,
If the small item setting level is set to 1A, which is half of that, feedback control is performed so that the input current becomes 2A, and even small metal items can be set to 2A, and the input setting level and the input detection level become equal. For example, if you set the input level to 12A, the input detection level for small metal objects will be approximately half that of 6A.
Since it does not reach the set level, it can be determined that it is a small item.
本発明は、従来の欠点を除き、インバータ回路
部品の電圧又は電流と、入力電流を比較して、小
物検知を行なうもので、小物金属の検知が確実に
行なえ、広範囲に連続的な出力制御が可能とな
る。 The present invention eliminates the conventional drawbacks and detects small objects by comparing the voltage or current of the inverter circuit components with the input current.The present invention enables reliable detection of small metal objects and provides continuous output control over a wide range. It becomes possible.
以下、図面に従がい詳細な説明を行なう。 A detailed explanation will be given below according to the drawings.
第１図は本発明による誘導加熱調理器用インバ
ータ装置の一実施例であり、第２図および第３図
は本発明の原理を示す特性図であり、第４図は本
発明による制御回路の一実施例のブロツクダイヤ
グラムである。 FIG. 1 is an embodiment of an inverter device for an induction cooking device according to the present invention, FIGS. 2 and 3 are characteristic diagrams showing the principle of the present invention, and FIG. 4 is an example of a control circuit according to the present invention. 1 is a block diagram of an example.
第１図において、低周波交流電源１より、整流
回路２に交流電圧を加えて、直流電圧に変換し、
直流電源を構成する。整流回路２の出力側には、
インバータ回路３を接続し、インバータ回路３は
直流電力を超音波周波数の高周波電力に変換す
る。インバータ回路３は、制御回路４により発振
制御され、インバータ回路３のパワースイツチン
グ半導体の導通パルス幅、もしくはインバータ発
振周波数を制御して、高周波出力電流を制御し、
誘導加熱出力を制御する。制御回路４の機能とし
て、各種保護装置、小物検知装置、あるいは出力
制御装置、およびパワースイツチング半導体の適
性な導通制御装置が含まれる。 In FIG. 1, an AC voltage is applied from a low frequency AC power source 1 to a rectifier circuit 2 and converted into a DC voltage,
Configure the DC power supply. On the output side of the rectifier circuit 2,
An inverter circuit 3 is connected, and the inverter circuit 3 converts DC power into high-frequency power at an ultrasonic frequency. The inverter circuit 3 is oscillated by the control circuit 4, and controls the conduction pulse width of the power switching semiconductor of the inverter circuit 3 or the inverter oscillation frequency to control the high frequency output current,
Control induction heating output. The functions of the control circuit 4 include various protection devices, small object detection devices, output control devices, and suitable conduction control devices for power switching semiconductors.
第１図に示すインバータ回路４は、直流入力端
子間に入力コンデンサ３０を接続し、入力コンデ
ンサと閉ループをなすように、加熱コイル３１と
パワースイツチング半導体３２を直列関係に接続
する。パワースイツチング半導体３２と逆並列関
係にダンパーダイオード３３を接続し、加熱コイ
ル３１と並列関係に、共振用コンデンサ３４を接
続する。共振用コンザンサ３４は、パワースイツ
チング半導体３２と並列接続しても動作は同じで
ある。 In the inverter circuit 4 shown in FIG. 1, an input capacitor 30 is connected between DC input terminals, and a heating coil 31 and a power switching semiconductor 32 are connected in series so as to form a closed loop with the input capacitor. A damper diode 33 is connected in antiparallel relation to the power switching semiconductor 32, and a resonance capacitor 34 is connected in parallel relation to the heating coil 31. The resonance condenser 34 operates in the same way even if it is connected in parallel with the power switching semiconductor 32.
パワースイツチング半導体３２の導通制御法と
して、加熱コイル３１の零電圧を検知して、パワ
ースイツチング半導体３２の導通パルス幅制御を
行なうもので、いわゆるPWM制御で出力制御が
可能である。誘導加熱コイル３１の電流を制御す
ることにより誘導加熱出力が制御できる。 As a method of controlling the conduction of the power switching semiconductor 32, the zero voltage of the heating coil 31 is detected and the conduction pulse width of the power switching semiconductor 32 is controlled, and the output can be controlled by so-called PWM control. By controlling the current of the induction heating coil 31, the induction heating output can be controlled.
制御回路４は、インバータ回路３の入力電流を
検知する入力電流検知用電流変成器４０とその入
力検知端子４１ａ，４１ｂ、パワースイツチング
半導体３２の制御端子へ接続されるドライブ出力
端子４２ａ，４２ｂ、電圧検知端子４３ａ，４３
ｂおよび出力電流検知端子４４とその出力検知端
子４５ａ，４５ｂを備える。制御回路４は、イン
バータ回路３の入力電流が所望の電流値となるよ
うに、パワースイツチング半導体３２のオンオフ
デユーテイを制御する。入力電流が一定になるよ
うに入力電力を制御すると、誘導加熱出力は、入
力電力に変換効率（約80％）を乗じた値となる。 The control circuit 4 includes an input current detection current transformer 40 that detects the input current of the inverter circuit 3, its input detection terminals 41a, 41b, drive output terminals 42a, 42b connected to the control terminal of the power switching semiconductor 32, Voltage detection terminals 43a, 43
b, an output current detection terminal 44, and its output detection terminals 45a and 45b. The control circuit 4 controls the on/off duty of the power switching semiconductor 32 so that the input current of the inverter circuit 3 has a desired current value. If the input power is controlled so that the input current is constant, the induction heating output will be the input power multiplied by the conversion efficiency (approximately 80%).
第２図は、パワースイツチング半導体３２の導
通パルス幅を制御して、インバータ回路３の入力
電流Ｉioを変えた時のパワースイツチング半導体
３２コレクタ電圧ＶCEの変化を示す。Ａは通常の
鍋、あるいは鍋底面積の大きい負荷であり、Ｂは
ナイフやスプーンの小物負荷である。破線Ｃは、
小物限界を示す。第２図において、小物負荷と、
通常の負荷を判別するには、入力電流Ｉioとコレ
クタ電圧ＶCEを比較すればよいことがわかる。す
なわち、所定の入力電流に対して、通常負荷で
は、コレクタ電圧ＶCEは、設定レベルＣよりも低
く、小物負荷では大きいことがわかる。この関係
は、入力電流Ｉioのすべての領域で成立するの
で、パワースイツチング半導体の導通パルス幅を
制御して、出力制御を行なう場合には、確実な小
物検知が可能である。なお、第２図のカツコ内に
示すように、縦軸はパワースイツチング半導体導
通パルス幅、又は導通パルス幅制御信号でもよ
く、また、加熱コイル３１の電圧ＶLでも同じで
ある。 FIG. 2 shows changes in the collector voltage V CE of the power switching semiconductor 32 when the input current I io of the inverter circuit 3 is changed by controlling the conduction pulse width of the power switching semiconductor 32. A is a normal pot or a load with a large bottom area of the pot, and B is a load of small items such as a knife or spoon. The broken line C is
Indicates the limit of small items. In Fig. 2, the accessory load and
It can be seen that in order to determine a normal load, it is sufficient to compare the input current Iio and the collector voltage VCE . That is, it can be seen that for a predetermined input current, the collector voltage V CE is lower than the set level C with a normal load, and larger with a small load. Since this relationship holds true in all regions of the input current Iio , reliable detection of small objects is possible when output control is performed by controlling the conduction pulse width of the power switching semiconductor. As shown in the box in FIG. 2, the vertical axis may be the power switching semiconductor conduction pulse width or the conduction pulse width control signal, or the voltage V L of the heating coil 31.
第３図は、加熱コイル電流ＩLと入力電流Ｉio
の関係をそれぞれの負荷について関係を示したも
ので、加熱コイル電流ＩLと入力電流Ｉioの比較
を行なうことにより、小物検知が可能である。 Figure 3 shows the heating coil current I L and the input current I io
The relationship is shown for each load, and small objects can be detected by comparing the heating coil current IL and the input current Iio .
第４図は、本発明による制御回路の一実施例を
示すブロツクダイヤグラムであり、コレクタ電圧
ＶCEを検知する電圧検知回路４６と入力電流を検
知する入力検知回路４７のそれぞれの出力信号を
比較回路４８に加え、小物検知を行なう。比較回
路４８の出力信号は、発振停止回路４９に加えら
れ、電圧検知回路４６の出力信号が、入力検知回
路４７の所定レベルよりも高ければ、インバータ
回路３の発振を停止し、ラツチさせる。なお、入
力検知回路４７の出力信号と、使用者調整可能な
入力設定回路５０の出力信号を、誤差増幅回路５
１に加え、その出力信号であるパルス幅設定信号
ＶSをパルス幅制御回路であるパワースイツチン
グ半導体の導通制御回路５２に加え、パワースイ
ツチング半導体３２の導通パルス幅を制御する。 FIG. 4 is a block diagram showing one embodiment of the control circuit according to the present invention, in which the output signals of the voltage detection circuit 46 for detecting the collector voltage V CE and the input detection circuit 47 for detecting the input current are compared with each other by a comparison circuit. In addition to 48, small object detection is performed. The output signal of the comparison circuit 48 is applied to an oscillation stop circuit 49, and if the output signal of the voltage detection circuit 46 is higher than a predetermined level of the input detection circuit 47, the oscillation of the inverter circuit 3 is stopped and latched. Note that the output signal of the input detection circuit 47 and the output signal of the user-adjustable input setting circuit 50 are transmitted to the error amplifier circuit 5.
1, the pulse width setting signal V S which is the output signal thereof is applied to the power switching semiconductor conduction control circuit 52 which is a pulse width control circuit to control the conduction pulse width of the power switching semiconductor 32.
第４図の他の実施例として、入力検知回路４７
の出力信号と、誤差増幅回路５１の出力信号ＶS
とを比較して小物検知できることは、第３図より
明らかである。 As another embodiment of FIG. 4, the input detection circuit 47
and the output signal of the error amplifier circuit 51 V S
It is clear from FIG. 3 that small objects can be detected by comparing the two.
以上述べた如く、本発明は、インバータ回路部
品の電圧又は電流と、入力電流の比較をして、小
物検知を行なうもので、広範囲な周波数による連
続出力制御を行なつても、確実な小物検知ができ
る特長がある。また入力電源電圧変動があつて
も、例えば、入力電流が下がると、コレクタ電圧
ＶCEも下がるので、電源電圧変動にかかわらず、
確実な小物検知が可能となり、入力電圧補正が不
必要である。また、パワースイツチング半導体の
コレクタ電圧あるいは加熱コイル電圧を検知する
には、それほど困難でなく、価格も高くならない
特長がある。 As described above, the present invention detects small objects by comparing the voltage or current of the inverter circuit components with the input current, and even if continuous output control is performed over a wide range of frequencies, reliable small object detection is possible. It has the feature of being able to Also, even if the input power supply voltage fluctuates, for example, if the input current decreases, the collector voltage V CE will also decrease, so regardless of the power supply voltage fluctuation,
Reliable detection of small objects is possible, and input voltage correction is unnecessary. Further, it has the advantage that it is not very difficult to detect the collector voltage of the power switching semiconductor or the heating coil voltage, and the cost is not high.
本発明は、実施例のインバータ回路に限らず、
ほとんどすべてのインバータ回路に応用可能で、
例えば、SCRインバータのトリガ周波数を変え
て出力制御する場合にも応用できる。 The present invention is not limited to the inverter circuit of the embodiment.
Applicable to almost all inverter circuits,
For example, it can be applied to output control by changing the trigger frequency of an SCR inverter.
第１図は本発明の一実施例における誘導加熱調
理器のインバータ装置の回路図、第２図は本発明
による小物検知法を示す入力電流とコレクタ電圧
あるいは加熱コイル電圧の特性図、第３図は本発
明の他の実施例を示す各種負荷での入力電流と加
熱コイル電流との関係特性図、第４図は本発明の
誘導加熱調理器の制御回路のブロツクダイヤグラ
ムである。
２……整流回路、３……インバータ回路、４…
…制御回路、３０……入力コンデンサ、３１……
加熱コイル、３２……パワースイツチング半導
体、３３……ダンパーダイオード、３４……共振
用コンデンサ、４０……入力電流検知用電流変成
器。
Fig. 1 is a circuit diagram of an inverter device for an induction heating cooker according to an embodiment of the present invention, Fig. 2 is a characteristic diagram of input current and collector voltage or heating coil voltage showing the small object detection method according to the present invention, and Fig. 3 4 is a characteristic diagram showing the relationship between input current and heating coil current at various loads showing another embodiment of the present invention, and FIG. 4 is a block diagram of a control circuit for an induction heating cooker according to the present invention. 2... Rectifier circuit, 3... Inverter circuit, 4...
...Control circuit, 30...Input capacitor, 31...
Heating coil, 32... Power switching semiconductor, 33... Damper diode, 34... Resonance capacitor, 40... Current transformer for input current detection.
Claims (1)
路と、上記直流電力を高周波電力に変換するイン
バータ回路と、その制御回路よりなり、前記制御
回路は、前記インバータ回路の入力電流を検知
し、前記インバータ回路部品の電圧又は電流とを
比較して小物負荷を検知することを特徴とする誘
導加熱調理器。 ２ 低周波交流電力を直流電力に変換する整流回
路と、上記直流電力を高周波電力に変換するイン
バータ回路と、その制御回路よりなり、上記制御
回路は前記インバータ回路の、パワースイツチン
グ半導体の導通間隔又は導通パルス幅を制御して
誘導加熱出力を制御するための入力検知回路、入
力設定回路、誤差増幅回路、発振制御回路およ
び、前記インバータ回路部品の電圧又は電流を検
知する電圧検知回路よりなり、前記入力検知回路
と前記電圧検知回路のそれぞれの出力信号を比較
して小物検知することを特徴とする誘導加熱調理
器。 ３ 直流電力を高周波電力に変換するインバータ
回路と、その制御回路よりなり、前記制御回路
は、前記インバータ回路のパワースイツチング半
導体導通パルス幅又はオンオフデユテイを制御す
る導通制御回路と、前記インバータ回路入力又は
出力に応じた信号と、前記導通制御回路のパルス
幅設定信号とを比較する小物検知装置を備えたこ
とを特徴とする誘導加熱調理器。[Scope of Claims] 1 Consists of a rectifier circuit that converts low-frequency AC power into DC power, an inverter circuit that converts the DC power into high-frequency power, and a control circuit thereof, and the control circuit is connected to the input of the inverter circuit. An induction heating cooker characterized in that a small object load is detected by detecting current and comparing it with the voltage or current of the inverter circuit component. 2 Consisting of a rectifier circuit that converts low-frequency AC power into DC power, an inverter circuit that converts the DC power into high-frequency power, and a control circuit thereof, the control circuit controlling the conduction interval of the power switching semiconductor of the inverter circuit. or an input detection circuit, an input setting circuit, an error amplification circuit, an oscillation control circuit for controlling the induction heating output by controlling the conduction pulse width, and a voltage detection circuit for detecting the voltage or current of the inverter circuit components, An induction heating cooker characterized in that small objects are detected by comparing respective output signals of the input detection circuit and the voltage detection circuit. 3. Consists of an inverter circuit that converts DC power into high-frequency power and its control circuit, the control circuit comprising a conduction control circuit that controls the power switching semiconductor conduction pulse width or on-off duty of the inverter circuit, and the inverter circuit. An induction heating cooker comprising: a small object detection device that compares a signal according to input or output with a pulse width setting signal of the conduction control circuit.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP109180A JPS5699992A (en) | 1980-01-09 | 1980-01-09 | Induction heating cooking oven |
| GB8035757A GB2062985B (en) | 1979-11-12 | 1980-11-06 | Small load detection by comparison between input and output parameters of an induction heat cooking apparatus |
| US06/205,861 US4356371A (en) | 1979-11-12 | 1980-11-10 | Small load detection by comparison between input and output parameters of an induction heat cooking apparatus |
| CA000364350A CA1167935A (en) | 1979-11-12 | 1980-11-10 | Small load detection by comparison between input and output parameters of an induction heat cooking apparatus |
| DE3042525A DE3042525C2 (en) | 1979-11-12 | 1980-11-11 | Induction heating cooker |
| AU64254/80A AU523782B2 (en) | 1979-11-12 | 1980-11-11 | Induction heat cooker |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP109180A JPS5699992A (en) | 1980-01-09 | 1980-01-09 | Induction heating cooking oven |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5699992A JPS5699992A (en) | 1981-08-11 |
| JPS6129117B2 true JPS6129117B2 (en) | 1986-07-04 |
Family
ID=11491823
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP109180A Granted JPS5699992A (en) | 1979-11-12 | 1980-01-09 | Induction heating cooking oven |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5699992A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010137498A1 (en) | 2009-05-26 | 2010-12-02 | 三菱電機株式会社 | Induction cooking device and induction heating method |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5860894U (en) * | 1981-10-20 | 1983-04-23 | ソニー株式会社 | Alarm generator for induction heating equipment |
| JPS58111291A (en) * | 1981-12-23 | 1983-07-02 | 株式会社東芝 | Induction heating cooking device |
| JPS58121589A (en) * | 1982-01-13 | 1983-07-19 | 三洋電機株式会社 | Induction heating cooling device |
| JPH0648636B2 (en) * | 1985-04-17 | 1994-06-22 | 三洋電機株式会社 | Induction heating device |
| JP2643251B2 (en) * | 1988-03-14 | 1997-08-20 | 松下電器産業株式会社 | Induction heating cooker |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5318841A (en) * | 1976-08-04 | 1978-02-21 | Matsushita Electric Ind Co Ltd | Induction heater |
| JPS5448346A (en) * | 1977-09-20 | 1979-04-16 | Sanyo Electric Co Ltd | Induction heating apparatus |
-
1980
- 1980-01-09 JP JP109180A patent/JPS5699992A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5318841A (en) * | 1976-08-04 | 1978-02-21 | Matsushita Electric Ind Co Ltd | Induction heater |
| JPS5448346A (en) * | 1977-09-20 | 1979-04-16 | Sanyo Electric Co Ltd | Induction heating apparatus |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010137498A1 (en) | 2009-05-26 | 2010-12-02 | 三菱電機株式会社 | Induction cooking device and induction heating method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5699992A (en) | 1981-08-11 |
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