EP0126984B1 - Electrical insulator having an insensitivity to pollution - Google Patents
Electrical insulator having an insensitivity to pollution Download PDFInfo
- Publication number
- EP0126984B1 EP0126984B1 EP84104677A EP84104677A EP0126984B1 EP 0126984 B1 EP0126984 B1 EP 0126984B1 EP 84104677 A EP84104677 A EP 84104677A EP 84104677 A EP84104677 A EP 84104677A EP 0126984 B1 EP0126984 B1 EP 0126984B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- coating
- zinc oxide
- insulator
- pollution
- layer
- 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
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B17/00—Insulators or insulating bodies characterised by their form
- H01B17/50—Insulators or insulating bodies characterised by their form with surfaces specially treated for preserving insulating properties, e.g. for protection against moisture, dirt, or the like
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B19/00—Apparatus or processes specially adapted for manufacturing insulators or insulating bodies
- H01B19/04—Treating the surfaces, e.g. applying coatings
Definitions
- the invention relates to electrical insulators having improved insensitivity to pollution and more particularly those whose dielectrics are made of glass or porcelain.
- the semiconductor layer plays practically no role, because it is the polluted layer which fixes the distribution of potential, irregularly.
- the present invention as defined by claim 1 overcomes these drawbacks.
- composition of the coating according to the invention is known per se and in use for certain electronic components called varistors - see for example document EP-A-0 000 864.
- varistors see for example document EP-A-0 000 864.
- a pollution problem surface and current distribution between a polluted layer and the underlying varistor does not arise for such components.
- a variation in the current density of the order of 10 6 corresponds to a variation in the voltage gradient close to 2.
- the coefficients k and ⁇ are characteristic of the material and geometric dimensions (in particular the insulator's creepage distance, coating thickness).
- the zinc oxide content in the coating is advantageously greater than 90%.
- Said metal oxide is advantageously chosen from the group formed by bismuth oxide, manganese oxide, cobalt oxide, chromium oxide, antimony oxide.
- the particular characteristic of the coating based on zinc oxide used in the context of the present invention is that it prevents the local formation of arcs in the dry areas.
- the distribution of the electric field on the surface of the insulator is improved and this prevents the bypass arc.
- the voltage can be stabilized below the threshold. bypass in the air.
- FIG. 1 there is shown a section 1 of an insulator constituted by an assembly of insulating elements such as 2.
- Each element 2 substantially comprises a dielectric 3 made of glass or porcelain for example, provided with a metal cover 4 and a metal connecting rod 5.
- the dielectric 3 is coated externally with a thin layer 6 based on zinc oxide doped with at least one other metal oxide.
- the layer 6 can have a thickness of between 0.05 and 0.5 mm.
- this mixture is sintered at 1250 ° C. and then, for 10 grams of product, 0.5 mole of Bi 2 0 3 (0.2691 g of Bi 2 0 3 ) is added.
- composition and thickness of the coating layer are adjusted according to the electrical characteristics desired for said layer.
- the shape of the insulator also comes into play.
- the establishment of the coating based on zinc oxide can be carried out according to various procedures.
- an insulator comprising a porcelain dielectric
- the powder is shaped, for example, by spraying or by vacuum deposition, in the form of a layer on the external surface of the dielectric.
- the thickness of the layer is chosen to be sufficient to be compatible with the overheating it will have to undergo during the operation of the insulator and according to the desired electrical characteristics.
- the deposition of the zinc oxide-based layer can be carried out in particular by vacuum deposition and spray deposition techniques.
- the measurements were made at 25 ° C.
- the curve (A) relates to a material corresponding to the composition of the first example mentioned above and the curve (B) to a semiconductor enamel used according to the prior art for coating a insulator.
- the intensity of the current which crosses the zinc oxide is very important, higher than 1000 amperes and being able to reach 30000 amperes, whereas in the insulator according to the invention, the intensity is between the milliamp and the amp.
- the action of the zinc oxide-based layer is local and manifests itself in several places at fairly short time intervals without causing the service to be interrupted.
- the action is instantaneous; it concerns the entire arrester, which is passed through entirely, and causes the service to stop by opening the line protection circuit breakers.
Abstract
Description
L'invention concerne les isolateurs électriques présentant une insensibilité améliorée à la pollution et plus particulièrement ceux dont les diélectriques sont en verre ou en porcelaine.The invention relates to electrical insulators having improved insensitivity to pollution and more particularly those whose dielectrics are made of glass or porcelain.
On sait que les pollutions atmosphériques peuvent conduire, sur la surface des isolateurs, à la formation de dépôts conducteurs.We know that atmospheric pollution can lead, on the surface of insulators, to the formation of conductive deposits.
La résistance électrique au niveau de la couche superficielle de l'isolateur n'étant pas uniforme, on constate en milieu humide, la présence de zones sèches en série avec des zones humides.Since the electrical resistance at the level of the surface layer of the insulator is not uniform, in wet conditions, the presence of dry zones in series with wet zones is observed.
Au niveau de ces zones sèches, il peut alors se produire des gradients de tension, bien plus élevés qu'au niveau des zones humides, et susceptibles d'atteindre le seuil de claquage dans l'air.At the level of these dry zones, voltage gradients can then occur, much higher than at the level of the wet zones, and capable of reaching the breakdown threshold in the air.
De plus lorsque l'étendue des zones sèches atteint une certaine proportion de la longueur de l'isolateur, il se produit alors un contour nement complet de ce dernier entraînant un court-circuit pour le réseau et sa mise hors service.In addition, when the extent of the dry zones reaches a certain proportion of the length of the insulator, there is then a complete bypass of the latter resulting in a short circuit for the network and its deactivation.
Afin de pallier ces inconvénients, il a déjà été proposé, dans le brevet US-A 3 795 499 pour les isolateurs en porcelaine et dans le brevet GB-A 1 240 854 pour les isolateurs organiques, de revêtir la surface du diélectrique par une couche semi-conductrice, de résistivité ne variant pas en fonction du courant, par exemple un émail semi-conducteur, de façon à juxtaposer à la couche polluée de résistivité irrégulière une couche sous-jacense de résistivité constante afin de maîtriser la répartition de potentiel le long de l'isolateur.In order to overcome these drawbacks, it has already been proposed, in patent US-A 3,795,499 for porcelain insulators and in patent GB-A 1,240,854 for organic insulators, to coat the surface of the dielectric with a layer semiconductor, of resistivity not varying according to the current, for example a semiconductor enamel, so as to juxtapose to the polluted layer of irregular resistivity an underlying layer of constant resistivity in order to control the distribution of potential along of the insulator.
Toutefois cette solution n'est pas pleinement satisfaisante.However, this solution is not fully satisfactory.
En effet, si le courant passant dans la couche semi-conductrice n'est pas nettement supérieur à celui qui passe dans la couche polluée, la couche semi-conductrice ne joue pratiquement pas de rôle, car c'est la couche polluée qui fixe la répartition du potentiel, de façon irrégulière.Indeed, if the current passing through the semiconductor layer is not significantly higher than that which passes through the polluted layer, the semiconductor layer plays practically no role, because it is the polluted layer which fixes the distribution of potential, irregularly.
Par contre, si le courant passant dans la couche semi-conductrice est nettement plus important que celui passant dans la couche polluée, les phénomènes résultant de la juxtaposition des zones sèches et des zones humides ne peuvent se produire, mais les pertes d'énergie sont alors trop élevées pour que cette solution soit économiquement acceptable. De plus, cette solution n'est pas fiable dans le temps.On the other hand, if the current passing through the semiconductor layer is significantly higher than that passing through the polluted layer, the phenomena resulting from the juxtaposition of dry zones and wet zones cannot occur, but the energy losses are then too high for this solution to be economically acceptable. In addition, this solution is not reliable over time.
On est donc obligé d'adopter une solution de compromis, qui n'est en fait satisfaisante que pour les cas de pollution légère.We are therefore obliged to adopt a compromise solution, which is in fact satisfactory only for cases of light pollution.
Aussi, avec un revêtement semi-conducteur de résistivité définie, on ne peut, dans les cas de pollution importante, qu'atténuer les défauts explicités ci-dessus mais non pas les supprimer.Also, with a semiconductor coating of defined resistivity, one can, in cases of significant pollution, only attenuate the defects explained above but not eliminate them.
La présente invention telle que définie par la revendication 1 permet de remédier à ces inconvénients.The present invention as defined by
Il est à noter ici que la composition du revêtement selon l'invention est connu en soi et en emploi pour certains composants électroniques s'appellant varistances - voir par exemple le document EP-A-0 000 864. Bien sûr, un problème de pollution de surface et de répartition de courant entre une couche polluée et la varistance sous-jacente ne se pose pas pour de tels composants.It should be noted here that the composition of the coating according to the invention is known per se and in use for certain electronic components called varistors - see for example document EP-A-0 000 864. Of course, a pollution problem surface and current distribution between a polluted layer and the underlying varistor does not arise for such components.
A titre d'exemple, dans le revétement conforme à l'invention, une variation de la densité de courant de l'ordre de 106 correspond à une variation du gradient de tension voisine de 2. Les coefficients k et α sont caractéristiques du matériau et des dimensions géométriques (notamment ligne de fuite de l'isolateur, épaisseur du revêtement).By way of example, in the coating according to the invention, a variation in the current density of the order of 10 6 corresponds to a variation in the voltage gradient close to 2. The coefficients k and α are characteristic of the material and geometric dimensions (in particular the insulator's creepage distance, coating thickness).
La teneur en oxyde de zinc dans le revêtement est avantageusement supérieure à 90%.The zinc oxide content in the coating is advantageously greater than 90%.
Ledit oxyde métallique est choisi avantageusement dans le groupe formé par l'oxyde de bismuth, l'oxyde de manganèse, l'oxyde de cobalt, l'oxyde de chrome, l'oxyde d'antimoine.Said metal oxide is advantageously chosen from the group formed by bismuth oxide, manganese oxide, cobalt oxide, chromium oxide, antimony oxide.
La caractéristique particulière du revêtement à base d'oxyde de zinc utilisée dans le cadre de la présente invention est qu'il évite la formation locale d'arcs au niveau des zones sèches. La répartition du champ électrique à la surface de l'isolateur est améliorée et on prévient ainsi l'arc de contournement.The particular characteristic of the coating based on zinc oxide used in the context of the present invention is that it prevents the local formation of arcs in the dry areas. The distribution of the electric field on the surface of the insulator is improved and this prevents the bypass arc.
Ainsi, en cas de pollution importante, compte tenu des caractéristiques électriques de la couche à base d'oxyde de zinc, lorsque l'intensité augmente très fortement dans la couche d'oxyde de zinc, la tension peut être stabilisée au-dessous du seuil de contournement dans l'air.Thus, in the event of significant pollution, taking into account the electrical characteristics of the layer based on zinc oxide, when the intensity increases very strongly in the layer of zinc oxide, the voltage can be stabilized below the threshold. bypass in the air.
Dès que les troubles résultant de la pollution diminuent, le courant revient à une valeur très faible ne créant pas de perte d'énergie sensible.As soon as the disturbances resulting from the pollution decrease, the current returns to a very low value not creating a significant loss of energy.
Ce fonctionnement se retrouve en cas de pollution légère, entrainant alors un très faible courant dans les zones polluées; le courant dans la couche superficielle à base d'oxyde de zinc est également très faible, ne créant pas de perte d'énergie sensible.This operation is found in the event of light pollution, thus causing a very weak current in the polluted zones; the current in the surface layer based on zinc oxide is also very weak, not creating a significant loss of energy.
D'autres caractéristiques de l'invention ressortiront de la description qui va suivre et du dessin annexé dans lequel:.
- La figure 1 représente schématiquement en coupe partielle une partie d'un isolateur conforme à l'invention.
- La figure 2 est représentative des caractéristiques électriques de l'oxyde de zinc dopé entrant dans la constitution du revêtement conforme à l'invention et d'un émail semi-conducteur utilisé selon l'art antérieur pour le revêtement des isolateurs.
- Figure 1 shows schematically in partial section part of an insulator according to the invention.
- FIG. 2 is representative of the electrical characteristics of doped zinc oxide forming part of the coating according to the invention and of a semiconductor enamel used according to the prior art for the coating of insulators.
Sur la figure 1, on a représenté un tronçon 1 d'un isolateur constitué par un assemblage d'éléments isolants tels que 2. Chaque élément 2 comprend substantiellement un diélectrique 3 en verre ou en porcelaine par exemple, muni d'un capot métallique 4 et d'une tige métallique de solidarisation 5.In Figure 1, there is shown a
Selon l'invention, le diélectrique 3 est revêtu extérieurement par une mince couche 6 à base d'oxyde de zinc dopé par au moins un autre oxyde métallique.According to the invention, the dielectric 3 is coated externally with a thin layer 6 based on zinc oxide doped with at least one other metal oxide.
La couche 6 peut présenter une épaisseur comprise entre 0,05 et 0,5 mm.The layer 6 can have a thickness of between 0.05 and 0.5 mm.
On donnera ci-après, à titre illustratif et nullement limitatif, trois exemples de composition d'une couche de revêtement:
- Pour 10 grammes de matériau de revêtement:
- For 10 grams of coating material:
Selon cet exemple, ce mélange est fritté à 1250°C puis, pour 10 grammes de produit, on ajoute 0,5 mole de Bi203 (0,2691 g de Bi203).According to this example, this mixture is sintered at 1250 ° C. and then, for 10 grams of product, 0.5 mole of Bi 2 0 3 (0.2691 g of Bi 2 0 3 ) is added.
La composition et l'épaisseur de la couche de revêtement sont ajustées en fonction des caractéristiques électriques désirées pour ladite couche.The composition and thickness of the coating layer are adjusted according to the electrical characteristics desired for said layer.
La forme de l'isolateur intervient également.The shape of the insulator also comes into play.
La mise en place du revêtement à base d'oxyde de zinc peut être réalisée selon différents procédes.The establishment of the coating based on zinc oxide can be carried out according to various procedures.
Ainsi, avec un isolateur comportant un diélectrique en porcelaine, on commence par réaliser ledit diélectrique.Thus, with an insulator comprising a porcelain dielectric, one begins by making said dielectric.
Le matériau destiné à constituer le revêtement est préparé ainsi:
- Le mélange pulvérulent d'oxyde de zinc et des oxydes métalliques additionnels est homogénéisé et broyé, puis subit un préfrittage à l'air ambiant vers 700° C pendant deux heures; le mélange calciné est rebroyé. De préférence on y incorpore ensuite un liant organique; on sèche l'ensemble par des moyens conventionnels et on rebroie le mélange obtenu: la granulométrie est alors de l'ordre du micron.
- The pulverulent mixture of zinc oxide and additional metal oxides is homogenized and ground, then undergoes pre-sintering in ambient air at around 700 ° C. for two hours; the calcined mixture is reground. Preferably, an organic binder is then incorporated therein; the assembly is dried by conventional means and the mixture obtained is rewound: the particle size is then of the order of a micron.
La poudre est mise en forme, par exemple, par projection ou par dépôt sous vide, sous forme d'une couche sur la surface externe du diélectrique. L'épaisseur de la couche est choisie suffisante pour être compatible avec les échauffements qu'elle aura à subir au cours du fonctionnement de l'isolateur et en fonction des caractéristiques électriques recherchées.The powder is shaped, for example, by spraying or by vacuum deposition, in the form of a layer on the external surface of the dielectric. The thickness of the layer is chosen to be sufficient to be compatible with the overheating it will have to undergo during the operation of the insulator and according to the desired electrical characteristics.
De même, pour un isolateur en verre, le dépôt de la couche à base d'oxyde de zinc peut être réalisé notamment par les techniques de dépôt sous vide et de dépôt par projection.Similarly, for a glass insulator, the deposition of the zinc oxide-based layer can be carried out in particular by vacuum deposition and spray deposition techniques.
Sur la figure 2, on a porté en ordonnée le logarithme du gradient de tension E en kV/cm et en abscisse le logarithme de la densité de courant J en ampères/cm2.In FIG. 2, the logarithm of the voltage gradient E in kV / cm is plotted on the ordinate and the logarithm of the current density J in amperes / cm2 on the abscissa.
Les mesures ont été faites à 25° C. La courbe (A) est relative à un matériau répondant à la composition du premier exemple précité et la courbe (B) à un émail semiconducteur utilisé selon l'art antérieur pour le revêtement d'un isolateur.The measurements were made at 25 ° C. The curve (A) relates to a material corresponding to the composition of the first example mentioned above and the curve (B) to a semiconductor enamel used according to the prior art for coating a insulator.
Comme on peut le constater très clairement sur la courbe (A), lorsque la densité de courant varie de 10-4 à 10+2, c'est-à-dire dans un rapport 106, la tension ne varie même pas dans un rapport 2, alors que dans le cas de l'émail semi-conducteur (courbe B) lorsque l'intensité varie dans le rapport 10, la tension varie également dans le même rapport 10.As can be seen very clearly in the curve (A), when the current density ranges from 10- 4 to 10 + 2, that is to say in a ratio of 10 6, the voltage does not vary even in a
Pour l'oxyde de zinc additionné d'oxydes métalliques, la courbe (A) répond à l'équation: I = k V a, α étant compris entre 20 et 50.For zinc oxide added with metal oxides, the curve (A) corresponds to the equation: I = k V a, α being between 20 and 50.
Si de telles propriétés électriques ont déjà été utilisées dans le domaine des parafoudres, il y a lieu de souligner que cette application diffère totalement de celle décrite dans la présente demande et que les résultats observés dans le cas des parafoudres ne peuvent être transposés aux isolateurs objet de la présente demande.If such electrical properties have already been used in the field of surge arresters, it should be emphasized that this application differs completely from that described in the present application and that the results observed in the case of surge arresters cannot be transposed to the object insulators. of this application.
En effet, dans les parafoudres, l'intensité du courant qui traverse l'oxyde de zinc est très importante, supérieure à 1000 ampères et pouvant atteindre 30000 ampères, alors que dans l'isolateur conforme à l'invention, l'intensité se situe entre le milliampère et l'ampère.Indeed, in the surge arresters, the intensity of the current which crosses the zinc oxide is very important, higher than 1000 amperes and being able to reach 30000 amperes, whereas in the insulator according to the invention, the intensity is between the milliamp and the amp.
Il s'ensuit en particulier, que la section d'oxyde de zinc dopé traversée dans un parafoudre est beaucoup plus importante que la section du revêtement de l'isolateur conforme à l'invention.It follows in particular that the cross-section of doped zinc oxide passed through in a surge arrester is much greater than the cross-section of the coating of the insulator according to the invention.
Dans le cas de l'isolateur conforme à l'invention, l'action de la couche à base d'oxyde de zinc est locale et se manifeste en plusieurs endroits selon des intervalles de temps assez courts sans entraîner l'interruption du service.In the case of the insulator according to the invention, the action of the zinc oxide-based layer is local and manifests itself in several places at fairly short time intervals without causing the service to be interrupted.
Par contre, dans les parafoudres, l'action est instantanée; elle concerne la totalité du parafoudre, qui est traversé entièrement, et entraîne l'arrêt du service par ouverture des disjoncteurs de protection de la ligne.On the other hand, in the surge arresters, the action is instantaneous; it concerns the entire arrester, which is passed through entirely, and causes the service to stop by opening the line protection circuit breakers.
Bien entendu l'invention n'est nullement limitée au mode de réalisation décrit et représenté qui n'a été donné qu'à titre d'exemple, en particulier elle peut s'appliquer à des isolateurs du type support ou d'autres types.Of course, the invention is in no way limited to the embodiment described and shown which has been given only by way of example, in particular it can be applied to insulators of the support type or of other types.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT84104677T ATE28533T1 (en) | 1983-04-29 | 1984-04-26 | POLLUTION RESISTANT ELECTRICAL INSULATOR. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8307100 | 1983-04-29 | ||
| FR8307100A FR2545259B1 (en) | 1983-04-29 | 1983-04-29 | ELECTRICAL INSULATOR HAVING IMPROVED POLLUTION INSENSITIVITY |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0126984A1 EP0126984A1 (en) | 1984-12-05 |
| EP0126984B1 true EP0126984B1 (en) | 1987-07-22 |
Family
ID=9288375
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP84104677A Expired EP0126984B1 (en) | 1983-04-29 | 1984-04-26 | Electrical insulator having an insensitivity to pollution |
Country Status (14)
| Country | Link |
|---|---|
| US (1) | US4563544A (en) |
| EP (1) | EP0126984B1 (en) |
| JP (1) | JPS59207515A (en) |
| AT (1) | ATE28533T1 (en) |
| AU (1) | AU564892B2 (en) |
| BR (1) | BR8401989A (en) |
| CA (1) | CA1250916A (en) |
| DE (1) | DE3464983D1 (en) |
| ES (1) | ES287936Y (en) |
| FR (1) | FR2545259B1 (en) |
| MX (1) | MX158055A (en) |
| NO (1) | NO164389C (en) |
| NZ (1) | NZ207972A (en) |
| ZA (1) | ZA843160B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4803100A (en) * | 1987-10-21 | 1989-02-07 | International Business Machines Corporation | Suspension and use thereof |
| US4835341A (en) * | 1988-03-08 | 1989-05-30 | Maxwell Laboratories, Inc. | Electrical insulator for use in plasma environment |
| US5548089A (en) * | 1994-01-13 | 1996-08-20 | Cooper Industries, Inc. | Bushing for gas-insulated switchgear |
| GB0103255D0 (en) * | 2001-02-09 | 2001-03-28 | Tyco Electronics Raychem Gmbh | Insulator arrangement |
| KR100910417B1 (en) | 2008-02-14 | 2009-08-04 | 삼광유리공업주식회사 | Tempered glass insulator and method of manufacturing the same |
| JP5663085B2 (en) * | 2010-05-28 | 2015-02-04 | ラップ インシュレータース ゲゼルシャフト ミット ベシュレンクテルハフツング | Composite insulator |
| FR3067164B1 (en) | 2017-06-02 | 2019-08-02 | Sediver Sa | PROCESS FOR TREATING A SUPER-HYDROPHOBIC PROTECTIVE COATING COMPONENT IN GLASS OR PORCELAIN |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB586064A (en) * | 1945-02-20 | 1947-03-05 | Taylor Tunnicliff And Company | An improved electrically-conductive ceramic coating or composition |
| US2576723A (en) * | 1946-10-11 | 1951-11-27 | Bullers Ltd | Electric insulator having potential drop controlling means |
| DE1003309B (en) * | 1954-05-17 | 1957-02-28 | Licentia Gmbh | High voltage insulator, especially outdoor insulator exposed to pollution |
| GB1112765A (en) * | 1965-06-01 | 1968-05-08 | Taylor Tunnicliff & Co Ltd | Improvements in or relating to semi-conducting ceramic glaze compositions |
| GB1240854A (en) * | 1968-09-27 | 1971-07-28 | British Railways Board | Improvements relating to high voltage electrical insulators |
| US3795499A (en) * | 1969-10-11 | 1974-03-05 | Ngk Insulators Ltd | Method of producing semi-conducting glaze compositions |
| US3627905A (en) * | 1969-12-08 | 1971-12-14 | British Railways Board | High-voltage electrical insulator having a predetermined surface conductance |
| DE2361204C3 (en) * | 1973-12-06 | 1978-11-23 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Electrical high-voltage device with insulating bodies |
| US4031498A (en) * | 1974-10-26 | 1977-06-21 | Kabushiki Kaisha Meidensha | Non-linear voltage-dependent resistor |
| CH601135A5 (en) * | 1976-07-01 | 1978-06-30 | Bbc Brown Boveri & Cie | |
| DE2735484C2 (en) * | 1977-08-05 | 1984-06-07 | Siemens AG, 1000 Berlin und 8000 München | Process for the production of thick film varistors with zinc oxide as the main component |
-
1983
- 1983-04-29 FR FR8307100A patent/FR2545259B1/en not_active Expired
-
1984
- 1984-04-23 US US06/602,676 patent/US4563544A/en not_active Expired - Fee Related
- 1984-04-26 NO NO841647A patent/NO164389C/en unknown
- 1984-04-26 CA CA000452824A patent/CA1250916A/en not_active Expired
- 1984-04-26 DE DE8484104677T patent/DE3464983D1/en not_active Expired
- 1984-04-26 AT AT84104677T patent/ATE28533T1/en not_active IP Right Cessation
- 1984-04-26 EP EP84104677A patent/EP0126984B1/en not_active Expired
- 1984-04-26 JP JP59085067A patent/JPS59207515A/en active Granted
- 1984-04-27 AU AU27441/84A patent/AU564892B2/en not_active Ceased
- 1984-04-27 ZA ZA843160A patent/ZA843160B/en unknown
- 1984-04-27 ES ES1984287936U patent/ES287936Y/en not_active Expired
- 1984-04-27 NZ NZ207972A patent/NZ207972A/en unknown
- 1984-04-27 MX MX201180A patent/MX158055A/en unknown
- 1984-04-27 BR BR8401989A patent/BR8401989A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| NZ207972A (en) | 1986-07-11 |
| NO841647L (en) | 1984-10-30 |
| ZA843160B (en) | 1985-07-31 |
| NO164389C (en) | 1990-09-26 |
| US4563544A (en) | 1986-01-07 |
| DE3464983D1 (en) | 1987-08-27 |
| JPS59207515A (en) | 1984-11-24 |
| AU2744184A (en) | 1984-11-01 |
| EP0126984A1 (en) | 1984-12-05 |
| FR2545259B1 (en) | 1985-12-27 |
| AU564892B2 (en) | 1987-08-27 |
| CA1250916A (en) | 1989-03-07 |
| JPH0247808B2 (en) | 1990-10-23 |
| FR2545259A1 (en) | 1984-11-02 |
| ATE28533T1 (en) | 1987-08-15 |
| BR8401989A (en) | 1984-12-04 |
| NO164389B (en) | 1990-06-18 |
| ES287936Y (en) | 1986-06-16 |
| ES287936U (en) | 1985-11-16 |
| MX158055A (en) | 1988-12-29 |
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