EP0727792A1 - High voltage transformer - Google Patents

High voltage transformer Download PDF

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Publication number
EP0727792A1
EP0727792A1 EP96400270A EP96400270A EP0727792A1 EP 0727792 A1 EP0727792 A1 EP 0727792A1 EP 96400270 A EP96400270 A EP 96400270A EP 96400270 A EP96400270 A EP 96400270A EP 0727792 A1 EP0727792 A1 EP 0727792A1
Authority
EP
European Patent Office
Prior art keywords
winding
secondary winding
voltage transformer
cheeks
transformer according
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.)
Ceased
Application number
EP96400270A
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German (de)
French (fr)
Inventor
Didier Calmettes
Joel Cousin
Claude Huron
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.)
Electromecanique du Nivernais Selni Ste
Original Assignee
Electromecanique du Nivernais Selni Ste
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Electromecanique du Nivernais Selni Ste filed Critical Electromecanique du Nivernais Selni Ste
Publication of EP0727792A1 publication Critical patent/EP0727792A1/en
Ceased legal-status Critical Current

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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
    • H05B6/64—Heating using microwaves
    • H05B6/66—Circuits
    • H05B6/662—Aspects related to the boost transformer of the microwave heating apparatus
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/32—Insulating of coils, windings, or parts thereof
    • H01F27/324—Insulation between coil and core, between different winding sections, around the coil; Other insulation structures
    • H01F27/325—Coil bobbins
    • 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
    • H05B6/64—Heating using microwaves
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
    • H01F2038/003—High frequency transformer for microwave oven

Definitions

  • the present invention relates to a high voltage transformer, in particular for supplying a magnetron in a microwave oven.
  • this type of transformer comprises a primary winding and two secondary windings, a first secondary winding connected between earth and the high voltage, and a second secondary winding, called heating, for starting the magnetron.
  • Document EP 0.364.171 also describes a transformer with a carcass comprising flat and parallel cheeks between them, spaced two by two to allow the winding of the first and second secondary windings, the two windings being superimposed along an axis perpendicular to the play.
  • the object of the present invention is to provide a transformer of the above type whose size is optimized in terms of the arrangement of the various windings, and whose manufacture is simple to implement.
  • the transformer according to the invention comprises a carcass 4 for supporting two windings of the transformer, a first secondary winding high voltage not shown so as not to overload the figures, and a second secondary heating winding 3 of the magnetron.
  • the carcass 4 is composed of a body 40 substantially parallelepiped, and three cheeks 41a, 41b and 41c substantially planar and parallel to each other.
  • the two cheeks 41a and 41b are spaced by a distance H to allow the winding of the first high voltage secondary winding in planes substantially parallel to the cheeks.
  • the cheeks 41b and 41c are also spaced so as to allow the winding of the second secondary winding 3.
  • this winding has few turns, typically of the order of four, the winding can be carried out on a single plane parallel to the cheeks, the size of this winding being reduced to the thickness of the wire.
  • the space 2 between the two cheeks 41b and 41c is preferably just sufficient to allow the thickness of the wire to pass. During the winding operation, one is thus certain of the exact positioning of the winding 3 along a plane.
  • the primary winding 1 of the transformer, the body 40 of the carcass 4 and the cheeks 41a to 41c have, in their center, a hole 6 substantially centered on the axis XX ', and of rectangular shape for example.
  • This hole 6 allows the passage of a core 70 of magnetic material, for the creation of magnetic fluxes.
  • this core 70 can constitute the central part of a first E-shaped part 7 of a sheet metal which will serve to hold all of the windings.
  • the carcass 4, provided with these two secondary windings and the primary winding 1 are superimposed along the axis XX 'in the window of E.
  • the cheek 41c which separates the primary winding 1 from the secondary heating winding 3 advantageously has a cutout, as shown in the figures.
  • Primary 1 can then be kept away from the heating coil 3 by two magnetic shunts 5 of substantially parallelepipedal shape placed in the cutouts, in full contact with the primary winding and the secondary heating winding, and allowing the transformer to operate in saturation.
  • the sheet metal further comprises a second part 8 in the form of I to close the window of the E once the primer is in place.
  • the two parts which form the sheet metal are for example made of magnetic steel.
  • the manufacture of the high voltage transformer is greatly simplified if the carcass is obtained in one piece, for example by molding a plastic material.
  • the material used must have good temperature resistance, in particular as regards its dielectric performance.
  • the two secondary windings are then wound up.
  • the primary winding being carried out separately, as well as the two parts of the sheet metal and the shunts, it suffices to assemble the different parts by stacking in the window the carcass, the shunts and the primary winding, then to close the window with the second part in I.

Abstract

The transformer comprises a shell (4) for supporting a primary winding (1), a first high tension secondary winding and a second secondary winding (3) used to heat the magnetron. The shell consists of a parallelepiped body (40) and a set of three plates (41a,41b,41c) which are plane and parallel to each other. Two plates (41a,41b) are separated by a distance (H) allowing the formation of the first high tension winding in planes parallel to the plates. The furthest plate (41c) is spaced from the second plate (41b) to allow the formation of the second secondary winding (3). This comprises only a few turns, typically only four in a single plane parallel to the plates.

Description

La présente invention a pour objet un transformateur haute tension, notamment pour l'alimentation d'un magnétron dans un four à micro-ondes.The present invention relates to a high voltage transformer, in particular for supplying a magnetron in a microwave oven.

Il est connu que ce type de transformateur comporte un enroulement primaire et deux enroulements secondaires, un premier enroulement secondaire connecté entre la masse et la haute tension, et un second enroulement secondaire, dit de chauffage, pour la mise en route du magnétron.It is known that this type of transformer comprises a primary winding and two secondary windings, a first secondary winding connected between earth and the high voltage, and a second secondary winding, called heating, for starting the magnetron.

Le document EP 0.364.171 décrit par ailleurs un transformateur avec une carcasse comprenant des joues planes et parallèles entre elles, espacées deux à deux pour permettre le bobinage du premier et du second enroulements secondaires, les deux enroulements se trouvant superposés selon un axe perpendiculaire aux joues.Document EP 0.364.171 also describes a transformer with a carcass comprising flat and parallel cheeks between them, spaced two by two to allow the winding of the first and second secondary windings, the two windings being superimposed along an axis perpendicular to the play.

Le but de la présente invention est de proposer un transformateur du type précédent dont l'encombrement soit optimisé au niveau de l'agencement des différents enroulements, et dont la fabrication soit simple à mettre en oeuvre.The object of the present invention is to provide a transformer of the above type whose size is optimized in terms of the arrangement of the various windings, and whose manufacture is simple to implement.

Ce but est atteint selon l'invention grâce à un transformateur haute tension pour l'alimentation d'un magnétron dans un four à micro-ondes tel que décrit dans les revendications 1 à 7.This object is achieved according to the invention by means of a high-voltage transformer for supplying a magnetron in a microwave oven as described in claims 1 to 7.

L'invention ainsi que ses avantages seront mieux compris au vu de la description suivante faite en référence aux figures annexées dans lesquelles :

  • La figure 1 est une vue en perspective de la carcasse supportant les deux enroulements secondaires selon un exemple de réalisation conforme à l'invention ;
  • Les figures 2a et 2b sont respectivement des vues en élévation et de dessus de la carcasse de la figure 1 ;
  • La figure 3 représente, en perspective, l'assemblage d'un transformateur haute tension conforme à l'invention.
The invention and its advantages will be better understood in view of the following description made with reference to the appended figures in which:
  • Figure 1 is a perspective view of the carcass supporting the two secondary windings according to an exemplary embodiment according to the invention;
  • Figures 2a and 2b are respectively an elevation and top view of the carcass of Figure 1;
  • Figure 3 shows, in perspective, the assembly of a high voltage transformer according to the invention.

Comme on peut le voir sur les différentes figures, le transformateur selon l'invention comporte une carcasse 4 pour supporter deux enroulements du transformateur, un premier enroulement secondaire haute tension non représenté pour ne pas surcharger les figures, et un second enroulement secondaire de chauffage 3 du magnétron. Les connexions de cet enroulement n'apparaissent pas sur les figures. Plus précisément, la carcasse 4 est composée d'un corps 40 sensiblement parallélépipédique, et de trois joues 41a, 41b et 41c sensiblement planes et parallèles entre elles. Les deux joues 41a et 41b sont espacées d'une distance H pour permettre le bobinage du premier enroulement secondaire haute tension selon des plans sensiblement parallèles aux joues. De la même manière, les joues 41b et 41c sont également espacées de manière à permettre le bobinage du second enroulement secondaire 3.As can be seen in the various figures, the transformer according to the invention comprises a carcass 4 for supporting two windings of the transformer, a first secondary winding high voltage not shown so as not to overload the figures, and a second secondary heating winding 3 of the magnetron. The connections of this winding do not appear in the figures. More specifically, the carcass 4 is composed of a body 40 substantially parallelepiped, and three cheeks 41a, 41b and 41c substantially planar and parallel to each other. The two cheeks 41a and 41b are spaced by a distance H to allow the winding of the first high voltage secondary winding in planes substantially parallel to the cheeks. Similarly, the cheeks 41b and 41c are also spaced so as to allow the winding of the second secondary winding 3.

Du fait que ce bobinage comporte peu de spires, typiquement de l'ordre de quatre, l'enroulement peut être réalisé sur un seul plan parallèle aux joues, l'encombrement de cet enroulement étant réduit à l'épaisseur du fil. Pour faciliter ce bobinage, l'espace 2 entre les deux joues 41b et 41c est de préférence juste suffisant pour permettre à l'épaisseur du fil de passer. Lors de l'opération de bobinage, on est ainsi certain du positionnement exacte de l'enroulement 3 selon un plan.Because this winding has few turns, typically of the order of four, the winding can be carried out on a single plane parallel to the cheeks, the size of this winding being reduced to the thickness of the wire. To facilitate this winding, the space 2 between the two cheeks 41b and 41c is preferably just sufficient to allow the thickness of the wire to pass. During the winding operation, one is thus certain of the exact positioning of the winding 3 along a plane.

Lorsque les deux enroulements sont présents sur la carcasse, ils sont, selon l'invention, superposés selon un axe XX' perpendiculaires aux joues.When the two windings are present on the carcass, they are, according to the invention, superimposed along an axis XX 'perpendicular to the cheeks.

Comme on peut le voir sur les figures 1, 2b et 3, l'enroulement primaire 1 du transformateur, le corps 40 de la carcasse 4 et les joues 41a à 41c comportent, en leur centre, un trou 6 sensiblement centré sur l'axe XX', et de forme par exemple rectangulaire. Ce trou 6 permet le passage d'un noyau 70 en matériau magnétique, pour la création des flux magnétiques. Avantageusement, comme représenté sur la figure 3, ce noyau 70 peut constituer la partie centrale d'une première partie 7 en forme de E d'une tôlerie qui va servir de maintien à l'ensemble des enroulements.As can be seen in Figures 1, 2b and 3, the primary winding 1 of the transformer, the body 40 of the carcass 4 and the cheeks 41a to 41c have, in their center, a hole 6 substantially centered on the axis XX ', and of rectangular shape for example. This hole 6 allows the passage of a core 70 of magnetic material, for the creation of magnetic fluxes. Advantageously, as shown in FIG. 3, this core 70 can constitute the central part of a first E-shaped part 7 of a sheet metal which will serve to hold all of the windings.

Plus précisément, la carcasse 4, munie de ces deux enroulements secondaires et l'enroulement primaire 1 sont superposés selon l'axe XX' dans la fenêtre du E.More specifically, the carcass 4, provided with these two secondary windings and the primary winding 1 are superimposed along the axis XX 'in the window of E.

Pour ne pas ajouter à l'épaisseur de l'ensemble, la joue 41c qui sépare l'enroulement primaire 1 de l'enroulement secondaire de chauffage 3 présente avantageusement une découpe, comme montrée sur les figures. Le primaire 1 peut alors être tenu à distance de l'enroulement de chauffage 3 par deux shunts magnétiques 5 de forme sensiblement parallélépipédique placés dans les découpes, en contact intégral avec l'enroulement primaire et l'enroulement secondaire de chauffage, et permettant au transformateur de fonctionner en saturation.In order not to add to the thickness of the assembly, the cheek 41c which separates the primary winding 1 from the secondary heating winding 3 advantageously has a cutout, as shown in the figures. Primary 1 can then be kept away from the heating coil 3 by two magnetic shunts 5 of substantially parallelepipedal shape placed in the cutouts, in full contact with the primary winding and the secondary heating winding, and allowing the transformer to operate in saturation.

Selon la figure 3, la tôlerie comporte en outre une seconde partie 8 en forme de I pour fermer la fenêtre du E une fois que le primaire est mis en place. Les deux pièces qui forment la tôlerie sont par exemple en acier magnétique.According to Figure 3, the sheet metal further comprises a second part 8 in the form of I to close the window of the E once the primer is in place. The two parts which form the sheet metal are for example made of magnetic steel.

La fabrication du transformateur haute tension se voit grandement simplifiée si la carcasse est obtenue d'une seule pièce, par exemple par moulage d'un matériau plastique. Le matériau utilisé doit présenter une bonne tenue en température, notamment en ce qui concerne ses performances diélectriques.The manufacture of the high voltage transformer is greatly simplified if the carcass is obtained in one piece, for example by molding a plastic material. The material used must have good temperature resistance, in particular as regards its dielectric performance.

Une fois que la carcasse est obtenue, on enroule alors les deux enroulements secondaires. L'enroulement primaire étant réalisé séparément, de même que les deux parties de la tôlerie et les shunts, il suffit alors d'assembler les différentes pièces en empilant dans la fenêtre la carcasse, les shunts et l'enroulement primaire, puis de fermer la fenêtre avec la seconde partie en I.Once the carcass is obtained, the two secondary windings are then wound up. The primary winding being carried out separately, as well as the two parts of the sheet metal and the shunts, it suffices to assemble the different parts by stacking in the window the carcass, the shunts and the primary winding, then to close the window with the second part in I.

En choisissant de superposer les différents enroulements en utilisant une carcasse, on a pu optimiser le remplissage de la fenêtre du E, en minimisant au maximum la place perdue dans cette fenêtre. Par ailleurs, on a optimisé également la longueur du fil de chauffage utilisé pour l'enroulement de chauffage.By choosing to superimpose the different windings using a carcass, we were able to optimize the filling of the E window, minimizing the space lost in this window. Furthermore, the length of the heating wire used for the heating coil has also been optimized.

Claims (7)

Transformateur haute tension pour l'alimentation d'un magnétron dans un four à micro-ondes, du type comportant un enroulement primaire (1), un premier enroulement secondaire haute tension et un second enroulement secondaire (3) pour le chauffage du magnétron, le transformateur comportant en outre une carcasse (4) constituée d'un corps (40) et de trois joues (41a, 41b, 41c) sensiblement planes et parallèles entre elles, les trois joues étant espacées deux à deux pour permettre le bobinage autour du corps, d'une part, du premier enroulement secondaire, et d'autre part, du second enroulement secondaire, les deux enroulements se trouvant superposés selon un axe perpendiculaire aux joues, caractérisé en ce que ledit corps est sensiblement parallélépipédique, en ce que l'enroulement primaire est placé parallèlement à côté du second enroulement secondaire selon ledit axe, et séparé dudit second enroulement par deux shunts magnétiques (5) et en ce que la joue (41c) séparant l'enroulement primaire (1) du second enroulement secondaire (3) présente une découpe de manière à ce que les shunts magnétiques soient intégralement en contact avec l'enroulement primaire et le second enroulement secondaire.High-voltage transformer for supplying a magnetron to a microwave oven, of the type comprising a primary winding (1), a first high-voltage secondary winding and a second secondary winding (3) for heating the magnetron, the transformer further comprising a carcass (4) consisting of a body (40) and three cheeks (41a, 41b, 41c) substantially plane and parallel to each other, the three cheeks being spaced two by two to allow winding around the body , on the one hand, of the first secondary winding, and on the other hand, of the second secondary winding, the two windings being superimposed along an axis perpendicular to the cheeks, characterized in that said body is substantially parallelepipedic, in that the primary winding is placed parallel to the second secondary winding along said axis, and separated from said second winding by two magnetic shunts (5) and in that the cheek (41c) separates ant the primary winding (1) of the second secondary winding (3) has a cutout so that the magnetic shunts are fully in contact with the primary winding and the second secondary winding. Transformateur haute tension selon la revendication 1, caractérisé en ce que la carcasse est obtenue par moulage d'un matériau plastique.High-voltage transformer according to claim 1, characterized in that the carcass is obtained by molding a plastic material. Transformateur haute tension selon l'une quelconque des revendications précédentes, caractérisé en ce que l'enroulement primaire, les trois joues et le corps comportent en leur milieu un trou (6) sensiblement centré sur l'axe pour permettre le passage d'un noyau (70) en matériau magnétique.High voltage transformer according to any one of the preceding claims, characterized in that the primary winding, the three cheeks and the body have in their center a hole (6) substantially centered on the axis to allow the passage of a core (70) made of magnetic material. Transformateur haute tension selon la revendication 3, caractérisé en ce que le noyau (70) constitue la partie centrale s'étendant le long de l'axe d'une première partie (7) en forme de E d'une tôlerie, dans la fenêtre duquel sont placés les enroulements.High-voltage transformer according to Claim 3, characterized in that the core (70) constitutes the central part extending along the axis of a first E-shaped part (7) of a sheet metal work, in the window from which the windings are placed. Transformateur haute tension selon la revendication 4, caractérisé en ce que la tôlerie comporte une seconde partie (8) en forme de I venant fermer la première partie (7) en forme de E.High voltage transformer according to claim 4, characterized in that the sheet metal work comprises a second part (8) in the form of I coming to close the first part (7) in the form of E. Transformateur haute tension selon l'une quelconque des revendications 4 et 5, caractérisé en ce que la tôlerie est en acier magnétique.High voltage transformer according to any one of claims 4 and 5, characterized in that the sheet metal is made of magnetic steel. Transformateur haute tension selon l'une quelconque des revendications précédentes, caractérisé en ce que les deux joues (41b, 41c) délimitant le bobinage du second enroulement secondaire (3) sont suffisamment proches pour ne permettre audit bobinage d'être réalisé que dans un plan parallèle aux joues.High voltage transformer according to any one of the preceding claims, characterized in that the two cheeks (41b, 41c) delimiting the winding of the second secondary winding (3) are close enough to allow said winding to be produced only in one plane parallel to the cheeks.
EP96400270A 1995-02-17 1996-02-09 High voltage transformer Ceased EP0727792A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9501825 1995-02-17
FR9501825A FR2730850B1 (en) 1995-02-17 1995-02-17 HIGH VOLTAGE TRANSFORMER

Publications (1)

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EP0727792A1 true EP0727792A1 (en) 1996-08-21

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ID=9476238

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EP96400270A Ceased EP0727792A1 (en) 1995-02-17 1996-02-09 High voltage transformer

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US (1) US5660756A (en)
EP (1) EP0727792A1 (en)
JP (1) JPH08250348A (en)
FR (1) FR2730850B1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100341321B1 (en) * 1999-07-26 2002-06-21 윤종용 Transformer for a microwave oven

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1564080A1 (en) * 1965-07-06 1970-10-15 Heinemann Electric Co Spool, spool body and method of making a spool
GB2089764A (en) * 1980-11-25 1982-06-30 Legrand Sa Coil former for transformer
EP0294297A1 (en) * 1987-05-11 1988-12-07 Societe Pour L'application De L'optique Et De L'electronique A La Recherche Et A L'automatisation Optelec (Societe Anonyme) Electric transformer for a microwave oven
EP0364171A2 (en) * 1988-10-13 1990-04-18 Matsushita Electric Industrial Co., Ltd. Highfrequency heating apparatus using frequency-converter-type power supply

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3652968A (en) * 1971-01-26 1972-03-28 Westinghouse Electric Corp Telescoped electrical windings and method of making same
US3873883A (en) * 1973-09-25 1975-03-25 Basler Electric Co Positive ignition power supply for a magnetron
US4216455A (en) * 1978-04-06 1980-08-05 Litton Systems, Inc. Inductive device with precision wound coil
JPH01149338A (en) * 1987-12-04 1989-06-12 Toshiba Corp Magnetron driving device
JPH01154488A (en) * 1987-12-09 1989-06-16 Toshiba Corp Stepup transformer for microwave oven
JP2941484B2 (en) * 1991-05-31 1999-08-25 株式会社東芝 Plane transformer

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1564080A1 (en) * 1965-07-06 1970-10-15 Heinemann Electric Co Spool, spool body and method of making a spool
GB2089764A (en) * 1980-11-25 1982-06-30 Legrand Sa Coil former for transformer
EP0294297A1 (en) * 1987-05-11 1988-12-07 Societe Pour L'application De L'optique Et De L'electronique A La Recherche Et A L'automatisation Optelec (Societe Anonyme) Electric transformer for a microwave oven
EP0364171A2 (en) * 1988-10-13 1990-04-18 Matsushita Electric Industrial Co., Ltd. Highfrequency heating apparatus using frequency-converter-type power supply

Also Published As

Publication number Publication date
FR2730850B1 (en) 1997-03-14
FR2730850A1 (en) 1996-08-23
US5660756A (en) 1997-08-26
JPH08250348A (en) 1996-09-27

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