EP0491254B1 - Induction heating cooker - Google Patents

Induction heating cooker Download PDF

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Publication number
EP0491254B1
EP0491254B1 EP91121017A EP91121017A EP0491254B1 EP 0491254 B1 EP0491254 B1 EP 0491254B1 EP 91121017 A EP91121017 A EP 91121017A EP 91121017 A EP91121017 A EP 91121017A EP 0491254 B1 EP0491254 B1 EP 0491254B1
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EP
European Patent Office
Prior art keywords
cooking appliance
coil
appliance according
capacitor
frequency
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
Application number
EP91121017A
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German (de)
French (fr)
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EP0491254A2 (en
EP0491254A3 (en
Inventor
Gerard Dr.-Ing. Rilly
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TEM ELECTROMENAGER
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Tem Electromenager
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Filing date
Publication date
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Publication of EP0491254A2 publication Critical patent/EP0491254A2/en
Publication of EP0491254A3 publication Critical patent/EP0491254A3/en
Application granted granted Critical
Publication of EP0491254B1 publication Critical patent/EP0491254B1/en
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H05B6/12—Cooking devices
    • H05B6/1209—Cooking devices induction cooking plates or the like and devices to be used in combination with them

Definitions

  • the invention is based on an inductive cooking appliance according to the preamble of claim 1.
  • Such a cooking device is known from DE-OS 37 23 485.
  • Such an inductive cooking device contains a heating winding which is fed by a generator with an alternating current of approximately 5-30 A and 20-30 kHz.
  • the heating winding generates currents by induction in the walls of a saucepan on a hotplate, which heats the food in the saucepan.
  • Because of the relatively high power of 300 - 6000 W, such a cooking device creates magnetic stray fields which can disrupt consumers in the vicinity of the cooking area, in particular radio receivers. Means are therefore required to keep such stray fields low.
  • the invention has for its object to provide a defined suppression of certain interference frequencies in such a cooking device with simple constructive passive means.
  • the invention is based on the following knowledge.
  • the coil in the simplest case a single circularly bent conductor, forms an oscillating circuit with the capacitor.
  • the resonance frequency of the resonant circuit can be selected by choosing the capacitor.
  • the resonant circuit forms a suction circuit for a frequency that can be selected by the tuning and thereby brings about a desired strong damping of the respective interference frequency. A particularly good effect is achieved if, apart from the area of the hotplate itself, all other areas are surrounded by a metal shield.
  • the solution according to the invention is structurally simple. In the simplest case, it consists only of a circularly bent conductor in the form of a wire or a flat metal strip and a commercially available capacitor.
  • the energy loss of the interference suppression ring thus formed is low because it is not a short-circuit turn and essentially only reactive power is consumed in the ring.
  • a short-circuit ring would cause considerable power loss due to the induced current.
  • such a ring would not cause attenuation at certain frequencies, but only aperiodic attenuation, the effect of which would be too low for the suppression of the interference radiation.
  • Fig. 1 shows a hotplate 1, in which a heating coil 2 is arranged.
  • the cooking appliance is surrounded on all sides by a metal shielding housing 3 which has a round opening 4 only in the area of the hotplate 1.
  • the magnetic induction field generated by the winding 2 exits through this opening and penetrates into the saucepan for heating.
  • a gap 5 is formed through the opening 4 between the shielding housing 3 and the hotplate 1.
  • the ends of the conductor 6 are connected to one another via the commercially available capacitor C.
  • the generator 7 supplies the heating winding 2 with a current iH of 5 A - 30 A and a frequency of about 30 kHz.
  • the resonant circuit formed by the conductor 6 and the capacitor C is tuned to frequencies which are to be suppressed in the interference field emanating from the cooking appliance. These are in particular harmonics of the working frequency of the cooking device or frequencies of radio transmitters which can be received in the area of the cooking device and can be disturbed by the cooking device.
  • the capacitor C has, for example, a capacitance of the order of 1 »F.
  • the shielding housing 3 is preferably made of aluminum. To suppress different frequencies, several such interference suppression rings made of a conductor 6 and a capacitor C can be arranged next to one another or one above the other his.
  • the interference suppression ring formed does not necessarily have to lie in a gap between the shielding housing 3 and the hotplate 1. If necessary, it can also be arranged in the area of the heating winding 2.
  • the optimal position of the interference suppression ring is preferably determined empirically.
  • the coil is formed by a ring coil 8, which has approximately the shape of the conductor 6 in Fig. 1.
  • the two ends of the wire wound in a ring are again connected to one another via the capacitor C.
  • such a device forms a suction circuit 9 with an inductance L and a capacitor C.
  • FIG. 3 shows the frequency spectrum of an interference field measured in the vicinity of the cooking device.
  • two attenuation points are formed at the frequencies f1, f2. These attenuation points or traps have an attenuation of approximately 10 db and a bandwidth of 50-100 kHz.
  • the frequencies f1, f2 are preferably at harmonics of the working frequency, that is to say the frequency of the current iH, or also at frequencies of radio stations received.
  • the capacitor C is formed by an electronic circuit 10, the output of which represents a capacitance C.
  • the value of the capacitance C can be changed by a voltage Uc, which is taken from the potentiometer 11.
  • the voltage Uc can also be a control voltage which is derived from the amplitude of a measured interference component.
  • the amplitude of a specific interference component can be measured by a frequency-selective circuit.
  • the control voltage thus obtained changes the frequency of the suction circuit formed in such a way that the amplitude of the interference component is minimal.
  • Multiple devices according to FIG. 4 can thus selectively suppress a plurality of components of a defined frequency in the frequency spectrum of the cooking appliance and with a sufficient amplitude.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Induction Heating Cooking Devices (AREA)
  • Cookers (AREA)
  • Constitution Of High-Frequency Heating (AREA)

Abstract

2.1. As a result of the fundamental and especially of the harmonics of the operating frequency, an induction heating cooker generates in a known manner significant interference radiation which, inter alia, can interfere with broadcast reception. The object is to reduce the interference radiation of the heating cooker using simple means. <??>2.2. A coil (2) whose ends are connected via a capacitor (C) is arranged in the region of the opening (4) between the actual cooking plate (1) and a screening housing (3). <??>2.3. Especially for induction heating cookers with reduced interference radiation. <IMAGE>

Description

Die Erfindung geht aus von einem induktiven Kochgerät gemäß dem Oberbegriff des Anspruchs 1.The invention is based on an inductive cooking appliance according to the preamble of claim 1.

Ein derartiges Kochgerät ist bekannt durch die DE-OS 37 23 485. Ein derartiges induktives Kochgerät enthält eine Heizwicklung, die von einem Generator mit einem Wechselstrom von etwa 5 - 30 A und 20 - 30 kHz gespeist wird. Die Heizwicklung erzeugt durch Induktion in den Wänden eines darüber auf einer Kochplatte befindlichen Topfes Ströme, die das in dem Topf befindliche Kochgut erwärmen. Wegen der relativ hohen Leistung von 300 - 6000 W entstehen bei einem solchen Kochgerät magnetische Streufelder, die in der Nähe der Kochstelle befindliche Verbraucher wie insbesondere Funkempfangsgeräte stören können. Es sind daher Mittel erforderlich, um derartige Streufelder gering zu halten.Such a cooking device is known from DE-OS 37 23 485. Such an inductive cooking device contains a heating winding which is fed by a generator with an alternating current of approximately 5-30 A and 20-30 kHz. The heating winding generates currents by induction in the walls of a saucepan on a hotplate, which heats the food in the saucepan. Because of the relatively high power of 300 - 6000 W, such a cooking device creates magnetic stray fields which can disrupt consumers in the vicinity of the cooking area, in particular radio receivers. Means are therefore required to keep such stray fields low.

Es ist bekannt, das gesamte Kochgerät mit einer Abschirmung zu umgeben. Diese Abschirmung muß aber im Bereich der Kochplatte, auf die der Topf gestellt wird, eine Öffnung aufweisen, weil sonst das Induktionsfeld nicht austreten und in den Kochtopf gelangen kann. Durch diese unvermeidbare Öffnung kommt es indessen zum Austreten von Streufeldern, insbesondere auf Oberwellen der Arbeitsfrequenz.It is known to surround the entire cooking device with a shield. However, this shielding must have an opening in the area of the hotplate on which the pot is placed, because otherwise the induction field cannot escape and get into the saucepan. This unavoidable opening, however, leads to leakage of stray fields, in particular to harmonics of the working frequency.

Der Erfindung liegt die Aufgabe zugrunde, bei einem derartigen Kochgerät mit einfachen konstruktiven passiven Mitteln eine definierte Unterdrückung bestimmter Störfrequenzen zu schaffen.The invention has for its object to provide a defined suppression of certain interference frequencies in such a cooking device with simple constructive passive means.

Diese Aufgabe wird durch die im Anspruch 1 angegebene Erfindung gelöst. Vorteilhafte Weiterbildungen der Erfindung sind in den Unteransprüchen angegeben.This object is achieved by the invention specified in claim 1. Advantageous developments of the invention are specified in the subclaims.

Die Erfindung beruht auf folgender Erkenntnis. Die Spule, im einfachsten Fall ein einziger kreisförmig gebogener Leiter, bildet mit dem Kondensator einen Schwingkreis. Die Resonanzfrequenz des Schwingkreises ist durch Wahl des Kondensators wählbar. Der Schwingkreis bildet für das Induktionsfeld einen Saugkreis für eine durch die Abstimmung wählbare Frequenz und bewirkt dadurch eine erwünschte starke Dämpfung der jeweiligen Störfrequenz. Eine besonders gute Wirkung wird dann erreicht, wenn bis auf den Bereich der Kochplatte selbst alle anderen Bereiche durch eine Metallabschirmung umgeben sind.The invention is based on the following knowledge. The coil, in the simplest case a single circularly bent conductor, forms an oscillating circuit with the capacitor. The resonance frequency of the resonant circuit can be selected by choosing the capacitor. For the induction field, the resonant circuit forms a suction circuit for a frequency that can be selected by the tuning and thereby brings about a desired strong damping of the respective interference frequency. A particularly good effect is achieved if, apart from the area of the hotplate itself, all other areas are surrounded by a metal shield.

Die erfindungsgemäße Lösung ist konstruktiv einfach. Sie besteht im einfachsten Fall nur aus einem kreisförmig gebogenen Leiter in Form eines Drahtes oder eines Metallflachbandes und einem handelsüblichen Kondensator. Der Energieverlust des so gebildeten Entstörringes ist gering, weil es sich nicht um eine Kurzschlußwindung handelt und in dem Ring im wesentlichen nur Blindleistung verbraucht wird. Ein Kurzschlußring würde durch den induzierten Strom eine beträchtliche Verlustleistung bewirken. Außerdem würde ein derartiger Ring keine Dämpfung bei bestimmten Frequenzen, sondern nur eine aperiodische Dämpfung bewirken, deren Wirkung für die Unterdrückung der Störstrahlung Zu gering wäre.The solution according to the invention is structurally simple. In the simplest case, it consists only of a circularly bent conductor in the form of a wire or a flat metal strip and a commercially available capacitor. The energy loss of the interference suppression ring thus formed is low because it is not a short-circuit turn and essentially only reactive power is consumed in the ring. A short-circuit ring would cause considerable power loss due to the induced current. In addition, such a ring would not cause attenuation at certain frequencies, but only aperiodic attenuation, the effect of which would be too low for the suppression of the interference radiation.

Ein Ausführungsbeispiel der Erfindung wird im folgenden anhand der Zeichnung erläutert. Darin zeigen

Fig. 1
in vereinfachter Form ein Kochgerät mit dem erfindungsgemäßen Entstörring,
Fig. 2
eine besondere Ausbildung der Spule,
Fig. 3
im Prinzip unterdrückte Störfrequenzen in dem Frequenzspektrum und
Fig. 4
eine Weiterbildung der Erfindung.
An embodiment of the invention is explained below with reference to the drawing. Show in it
Fig. 1
in simplified form, a cooking appliance with the interference suppression ring according to the invention,
Fig. 2
a special design of the coil,
Fig. 3
in principle suppressed interference frequencies in the frequency spectrum and
Fig. 4
a development of the invention.

Fig. 1 zeigt eine Kochplatte 1, in der eine Heizwicklung 2 angeordnet ist. Das Kochgerät ist allseitig von einem Abschirmgehäuse 3 aus Metall umgeben, das nur im Bereich der Kochplatte 1 eine runde Öffnung 4 aufweist. Durch diese Öffnung tritt das durch die Wicklung 2 erzeugte magnetische Induktionsfeld aus und dringt zur Erwärmung in den Kochtopf ein. Durch die Öffnung 4 wird zwischen dem Abschirmgehäuse 3 und der Kochplatte 1 ein Spalt 5 gebildet. Die Enden des Leiters 6 sind über den handelsüblichen Kondensator C miteinander verbunden. Der Generator 7 versorgt die Heizwicklung 2 mit einem Strom iH von 5 A - 30 A und einer Frequenz von etwa 30 kHz.Fig. 1 shows a hotplate 1, in which a heating coil 2 is arranged. The cooking appliance is surrounded on all sides by a metal shielding housing 3 which has a round opening 4 only in the area of the hotplate 1. The magnetic induction field generated by the winding 2 exits through this opening and penetrates into the saucepan for heating. A gap 5 is formed through the opening 4 between the shielding housing 3 and the hotplate 1. The ends of the conductor 6 are connected to one another via the commercially available capacitor C. The generator 7 supplies the heating winding 2 with a current iH of 5 A - 30 A and a frequency of about 30 kHz.

In den Spalt 5 ist nur eine Spule eingelegt, die aus dem kreisförmig gebogenen Leiter 6 besteht. Der durch den Leiter 6 und den Kondensator C gebildete Schwingkreis ist auf Frequenzen abgestimmt, die in dem vom Kochgerät ausgehenden Störfeld unterdrückt werden sollen. Das sind insbesondere Oberwellen der Arbeitsfrequenz des Kochgerätes oder Frequenzen von Rundfunksendern, die im Bereich des Kochgerätes empfangen und durch das Kochgerät gestört werden können. Der Kondensator C hat z.B. eine Kapazität in der Größenordnung von 1 »F. Das Abschirmgehäuse 3 besteht vorzugsweise aus Aluminium. Zur Unterdrückung verschiedener Frequenzen können mehrere derartige Entstörringe aus einem Leiter 6 und einem Kondensator C nebeneinander oder übereinander angeordnet sein. Der gebildete Entstörring muß nicht unbedingt in einem Spalt zwischen dem Abschirmgehäuse 3 und der Kochplatte 1 liegen. Er kann gegebenenfalls auch im Bereich der Heizwicklung 2 angeordnet sein. Vorzugsweise wird die optimale Lage des Entstörringes empirisch ermittelt.In the gap 5, only one coil is inserted, which consists of the circularly bent conductor 6. The resonant circuit formed by the conductor 6 and the capacitor C is tuned to frequencies which are to be suppressed in the interference field emanating from the cooking appliance. These are in particular harmonics of the working frequency of the cooking device or frequencies of radio transmitters which can be received in the area of the cooking device and can be disturbed by the cooking device. The capacitor C has, for example, a capacitance of the order of 1 »F. The shielding housing 3 is preferably made of aluminum. To suppress different frequencies, several such interference suppression rings made of a conductor 6 and a capacitor C can be arranged next to one another or one above the other his. The interference suppression ring formed does not necessarily have to lie in a gap between the shielding housing 3 and the hotplate 1. If necessary, it can also be arranged in the area of the heating winding 2. The optimal position of the interference suppression ring is preferably determined empirically.

In Fig. 2 ist die Spule durch eine Ringspule 8 gebildet, die etwa die Form des Leiters 6 in Fig. 1 hat. Die beiden Enden des ringförmig aufgewickelten Drahtes sind wieder über den Kondensator C miteinander verbunden. Wie in Fig. 2 rechts dargestellt, bildet eine derartige Einrichtung einen Saugkreis 9 mit einer Induktivität L und einem Kondensator C.In Fig. 2 the coil is formed by a ring coil 8, which has approximately the shape of the conductor 6 in Fig. 1. The two ends of the wire wound in a ring are again connected to one another via the capacitor C. As shown on the right in FIG. 2, such a device forms a suction circuit 9 with an inductance L and a capacitor C.

Fig. 3 zeigt das Frequenzspektrum eines in der Nähe des Kochgerätes gemessenen Störfeldes. Durch zwei gemäß Fig. 1, 2 aufgebaute Entstörringe sind zwei Dämpfungsstellen bei den Frequenzen f1, f2 gebildet. Diese Dämpfungsstellen oder Fallen haben eine Dämpfung von etwa 10 db und eine Bandbreite von 50 - 100 kHz. Die Frequenzen f1, f2 liegen vorzugsweise bei Oberwellen der Arbeitsfrequenz, also der Frequenz des Stromes iH, oder auch bei Frequenzen empfangener Rundfunksender.3 shows the frequency spectrum of an interference field measured in the vicinity of the cooking device. 1, 2, two attenuation points are formed at the frequencies f1, f2. These attenuation points or traps have an attenuation of approximately 10 db and a bandwidth of 50-100 kHz. The frequencies f1, f2 are preferably at harmonics of the working frequency, that is to say the frequency of the current iH, or also at frequencies of radio stations received.

In Fig. 4 ist der Kondensator C durch eine elektronische Schaltung 10 gebildet, deren Ausgang eine Kapazität C darstellt. Der Wert der Kapazität C ist durch eine Spannung Uc veränderbar, die vom dem Potentiometer 11 abgenommen wird. Diese Lösung hat den Vorteil, daß eine einfache und sehr genaue Abstimmung des gebildeten Saugkreises auf eine bestimmte Frequenz erfolgen kann. Die Spannung Uc kann auch eine Regelspannung sein, die aus der Amplitude einer gemessenen Störkomponente abgeleitet wird. Durch eine frequenzselektive Schaltung kann die Amplitude einer bestimmten Störkomponente gemessen werden. Die daraus gewonnene Regelspannung ändert somit die Frequenz des gebildeten Saugkreises derart, daß die Amplitude der Störkomponente minimal ist. Durch mehrfache Einrichtungen gemäß Fig. 4 können somit im Frequenzspektrum des Kochgerätes mehrere Komponenten definierter Frequenz selektiv und mit ausreichender Amplitude unterdrückt werden.4, the capacitor C is formed by an electronic circuit 10, the output of which represents a capacitance C. The value of the capacitance C can be changed by a voltage Uc, which is taken from the potentiometer 11. This solution has the advantage that the suction circuit formed can be easily and very precisely tuned to a specific frequency. The voltage Uc can also be a control voltage which is derived from the amplitude of a measured interference component. The amplitude of a specific interference component can be measured by a frequency-selective circuit. The control voltage thus obtained changes the frequency of the suction circuit formed in such a way that the amplitude of the interference component is minimal. Multiple devices according to FIG. 4 can thus selectively suppress a plurality of components of a defined frequency in the frequency spectrum of the cooking appliance and with a sufficient amplitude.

Claims (10)

  1. Inductive cooking appliance with reduced interference radiation having a screening housing (3) with an opening (4) in the region of the cooking plate (1) containing the induction coil (2), characterized in that a coil (6), whose ends are connected via a capacitor (C), is arranged in the region of the opening (4).
  2. Cooking appliance according to Claim 1, characterized in that the coil (6) is located in an annular slot (5) between the outer edge of the cooking plate (1) and the edge of the opening (4).
  3. Cooking appliance according to Claim 1 or 2, characterized in that the coil consists of only one annularly bent conductor (6).
  4. Cooking appliance according to Claim 3, characterized in that the conductor is a flat metal strip.
  5. Cooking appliance according to Claim 1 or 2, characterized in that the coil is formed by an annular coil (8) having a multiplicity of turns (Fig. 2).
  6. Cooking appliance according to Claim 1, characterized in that the coil is tuned to a harmonic of the operating frequency of the cooking appliance.
  7. Cooking appliance according to Claim 1, characterized in that the coil is tuned to the frequency of a radial transmitter which can be picked up in the region of the cooking appliance.
  8. Cooking appliance according to Claim 1, characterized in that a plurality of coils (6), tuned to different frequencies (f1, f2), are provided with one capacitor (C) each.
  9. Cooking appliance according to Claim 1, characterized in that the capacitor (C) is formed by an electronic circuit (10) whose capacitance value (C) can be adjusted by means of an adjustable voltage for the purpose of matching to a desired frequency.
  10. Cooking appliance according to Claim 9, characterized in that the circuit (10) is controlled by a voltage (Uc) which is derived in a frequency-selective circuit from the amplitude of an interference component of the stray magnetic field of the cooking appliance.
EP91121017A 1990-12-17 1991-12-07 Induction heating cooker Expired - Lifetime EP0491254B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4040281 1990-12-17
DE4040281A DE4040281A1 (en) 1990-12-17 1990-12-17 INDUCTIVE COOKER

Publications (3)

Publication Number Publication Date
EP0491254A2 EP0491254A2 (en) 1992-06-24
EP0491254A3 EP0491254A3 (en) 1992-07-08
EP0491254B1 true EP0491254B1 (en) 1995-01-25

Family

ID=6420531

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91121017A Expired - Lifetime EP0491254B1 (en) 1990-12-17 1991-12-07 Induction heating cooker

Country Status (8)

Country Link
US (1) US5278381A (en)
EP (1) EP0491254B1 (en)
JP (1) JPH04315790A (en)
AT (1) ATE117866T1 (en)
CA (1) CA2057211A1 (en)
DE (2) DE4040281A1 (en)
DK (1) DK0491254T3 (en)
ES (1) ES2067132T3 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2726962B1 (en) * 1994-11-15 1996-12-13 Europ Equip Menager REDUCED PARASITE RADIATION INDUCTION COOKING APPARATUS
US5603858A (en) * 1995-06-02 1997-02-18 Aladdin Synergetics, Inc. Heat retentive server for induction heating
US5660754A (en) * 1995-09-08 1997-08-26 Massachusetts Institute Of Technology Induction load balancer for parallel heating of multiple parts
KR20040010014A (en) * 2002-07-19 2004-01-31 미츠비시덴키 가부시키가이샤 An inductive heating appliance for cooking
JPWO2013038694A1 (en) * 2011-09-14 2015-03-23 パナソニックＩｐマネジメント株式会社 Contactless power receiving device and contactless power transmission device
US20150163864A1 (en) * 2012-01-08 2015-06-11 Acess Business Group International LLC Inductive cooking system
EP3190860B1 (en) * 2014-09-05 2019-08-21 Nippon Steel Corporation Induction heating device for metal strip

Family Cites Families (14)

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Publication number Priority date Publication date Assignee Title
NL79043C (en) * 1950-06-23
US3742179A (en) * 1971-12-29 1973-06-26 Gen Electric Induction cooking appliance including wireless transmission of temperature data
US3761668A (en) * 1972-03-01 1973-09-25 Gen Electric Small electrical apparatus powered by induction cooking appliances
DE7333691U (en) * 1972-09-18 1974-03-14 Wec Inductive cooker
US3979572A (en) * 1974-10-29 1976-09-07 Mitsubishi Denki Kabushiki Kaisha Induction heating apparatus
US3996442A (en) * 1975-01-20 1976-12-07 Westinghouse Electric Corporation Induction heating coil assembly for heating cooking vessels
DE2643449A1 (en) * 1976-09-27 1978-03-30 Siemens Ag Inductive heating plate for cooker - has ferrite base with bifilar spiral or meander coil in slots covered by ceramic
DE2754963A1 (en) * 1977-12-09 1979-06-13 Bosch Siemens Hausgeraete Induction-heating hob unit for cooker - has power stage AC and DC decoupled from main housing to prevent radiation of RF interference
JPS577082A (en) * 1980-06-13 1982-01-14 Riccar Sewing Machine Kk Exciter for induction heater
US4348571A (en) * 1981-03-18 1982-09-07 General Electric Company Flux shaping arrangement for induction surface unit
DE3217850A1 (en) * 1982-05-12 1983-11-17 Bosch-Siemens Hausgeräte GmbH, 7000 Stuttgart Induction heating cooker
GB2198020B (en) * 1986-11-25 1990-10-10 Ti Creda Ltd Improvements in or relating to induction heating coils for cooking appliances
DE3723485A1 (en) * 1987-07-16 1989-01-26 Thomson Brandt Gmbh Inductive cooking point
FR2646049B1 (en) * 1989-04-18 1991-05-24 Cableco Sa REMOVABLE ELECTRIC HEATER PLATE

Also Published As

Publication number Publication date
DE4040281A1 (en) 1992-07-02
EP0491254A2 (en) 1992-06-24
DE59104410D1 (en) 1995-03-09
JPH04315790A (en) 1992-11-06
ES2067132T3 (en) 1995-03-16
DK0491254T3 (en) 1995-07-10
ATE117866T1 (en) 1995-02-15
EP0491254A3 (en) 1992-07-08
US5278381A (en) 1994-01-11
CA2057211A1 (en) 1992-06-18

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