EP0622813A1 - Resistive element for power resistor - Google Patents

Resistive element for power resistor Download PDF

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Publication number
EP0622813A1
EP0622813A1 EP94400913A EP94400913A EP0622813A1 EP 0622813 A1 EP0622813 A1 EP 0622813A1 EP 94400913 A EP94400913 A EP 94400913A EP 94400913 A EP94400913 A EP 94400913A EP 0622813 A1 EP0622813 A1 EP 0622813A1
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EP
European Patent Office
Prior art keywords
slots
resistive element
plate
electrical
resistive
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.)
Granted
Application number
EP94400913A
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German (de)
French (fr)
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EP0622813B1 (en
Inventor
Olivier Couderc
Bernard Puel
Joseph Teixido
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Alstom Transport SA
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GEC Alsthom Transport SA
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Publication of EP0622813A1 publication Critical patent/EP0622813A1/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C3/00—Non-adjustable metal resistors made of wire or ribbon, e.g. coiled, woven or formed as grids
    • H01C3/10—Non-adjustable metal resistors made of wire or ribbon, e.g. coiled, woven or formed as grids the resistive element having zig-zag or sinusoidal configuration
    • H01C3/12—Non-adjustable metal resistors made of wire or ribbon, e.g. coiled, woven or formed as grids the resistive element having zig-zag or sinusoidal configuration lying in one plane

Definitions

  • the present invention relates to a resistive element for power resistance.
  • Some power resistors use metallic strips or plates as a resistive part. This is the case in particular of the power resistors used in rail traction as a braking rheostat. To limit overheating and wear on mechanical brakes, a significant part of the kinetic energy of the machine is converted into electrical energy dissipated in thermal form in power rheostats. These resistors must withstand the harsh service conditions encountered in rail traction. These rheostats are in the form of boxes which are combined to obtain the desired total resistance. Each box has a resistive part generally made from an alloy of nickel and chromium. The resistive part can be constituted in different ways, for example by strips folded in a zigzag and welded end to end or by plates connected in series.
  • the resistive part of the power resistor can consist of a dimensioned ribbon, from the manufacturing, in width, thickness and length.
  • the resistivity is defined during casting, the rolling determines its thickness, the cutting its width and the flow its length.
  • This method has several drawbacks.
  • the supply time is long (four or five months) since the interventions take place from the metal casting.
  • the manufacturing cost is high since the parts are made on demand.
  • resistive plates sold by the French company RESISTEL S.A. which have slots always perpendicular to the length of the plates (see Figure 1).
  • the resistance value is a function of the pitch imposed on the transverse slots. This solution turns out to be much more satisfactory than the previous ones: there is no local alteration in resistance, the slits being able to be made without roughing up the metal.
  • the pitch of the slots allowing the resistance to be adjusted, the variations in thickness and resistivity of plates of different origins can thus be compensated.
  • a resistive element is proposed, in the form of a plate or ribbon, several of which can be combined to constitute a power resistance, this resistive element having slots inclined at a determined angle.
  • the angle of inclination of the slots and the pitch of these slots makes it possible to finely adjust the value of the resistance of the resistive element (up to a hundredth of an ohm).
  • the subject of the invention is therefore a resistive element constituted by a strip of resistive material in which are made, according to a determined pitch, slots delimiting at least one zigzag electrical circuit between two ends of the resistive element serving as electrical connections, characterized in that said slots are inclined, with respect to an axis passing through said electrical connections, by an angle of determined value to give said resistive element the desired electrical resistance.
  • the strip can advantageously have the form of a plate.
  • the resistive element may comprise several electrical circuits joined in parallel by said ends. This has the advantage of giving great flexibility in adjusting the resistance. In this case, one can act on the pitch of the slots, their angle of inclination and the number of electrical circuits.
  • the electrical circuits can be delimited by slots made from the edges of the strip joining said ends and by internal slots made inside the strip.
  • an additional slot may advantageously be provided between the end of an electrical circuit and the corresponding end of the resistive element if this end of the electrical circuit is between an internal slot and one of said edges of the bandaged.
  • the resistive element can comprise in series several electrical circuits in parallel.
  • FIG. 1 represents, seen from above, a resistive plate according to the known art.
  • the rectangular plate 1 in alloy of nickel and chromium, has two opposite ends 2 and 3 by which the plate will be fixed in a rheostat comprising a plurality of identical plates. These ends 2 and 3 also serve as electrical connections for placing the various resistive plates of the rheostat in series according to a method well known to those skilled in the art. Holes 4 and 5 drilled in the middle position in the ends 2 and 3 can ensure both the mechanical maintenance of the plates and their placing in series.
  • Slots are made in the plate from the edges 6 and 7 joining the ends 2 and 3: slots 8 made from the edge 6 and slots 9 made from the edge 7.
  • the slots 8 and 9 are located alternately so as to form a zigzag electrical circuit between the ends 2 and 3.
  • the slots 8 and 9 are perpendicular to the edges 6 and 7 of the resistive plate 1 and are therefore perpendicular to an axis passing through the holes 4 and 5.
  • the value of the resistance of the plate 1 is adjusted by adjusting the pitch of the regularly spaced slots 8 and 9. Since the plate has a plurality of slots, it is difficult from a single variable to precisely adjust the value of its resistance. This difficulty increases with the number of slots.
  • Figure 2 is a top view of a resistive plate 10 according to the invention. It is a rectangular plate, for example made of nickel-chrome, which has two opposite ends 11 and 12. Holes 13 and 14 drilled in these ends serve for the mechanical fixing of the plate 10 as well as for its electrical connection. An additional hole 15 in the central part ensures intermediate mechanical support of the same type as for the ends.
  • the edges 16 and 17 of the plate 10 join the ends 11 and 12. From the edge 16, slots were made 18. From the edge 17, slots 19 were made.
  • the interior of the plate 10 has a series of slots 20 in its upper part, according to the view in FIG. 2. It also has a series of slots 21 in its lower part.
  • the slots delimit three electrical circuits in parallel on the left side of the plate and three electrical circuits in parallel on the right side. One of these circuits is shown in dotted lines.
  • the plate 10 therefore comprises in series two assemblies each comprising three electrical circuits in parallel.
  • the internal slots 20 and 21 are all the same length and the slots 18 and 19 of the plate edges are half length.
  • the pitch between two successive slots is the same for the entire plate and the angle of inclination is of course always the same.
  • the slots 18, 19, 20 and 21 are inclined at the same angle ⁇ relative to the longitudinal axis of the plate.
  • the resistance of the plate depends on its own characteristics (resistivity, dimensions), the number of its electrical circuits, the pitch of the slots and also the angle of inclination of these slots.
  • FIG. 3 shows the range of evolution of the resistance R of the plate 10 as a function of the angle of inclination ⁇ for values between 45 and 80 ° and as a function of the dimensions of the plate, the pitch of the slots and the number of electrical circuits.
  • the ordinate axis is graduated in relative values. For the upper curve delimiting the range, it can be seen that for angle values approaching 45 °, the variation in resistance is small. For values approaching 80 °, the resistance variation is significant.
  • the range between 60 and 70 ° is interesting because it allows good control of the resistance variation as a function of the angle of inclination.
  • the slots are inclined by about 66 °.
  • the remedy for avoiding the appearance of excessively hot zones consists in providing an additional slit between the end of the electrical circuit in question and the corresponding end of the resistive element. This is shown in Figure 4 where there is shown a resistive plate 25, of the type of Figure 2, but having these additional slots referenced 26, of the same pitch and the same width as the others.
  • the slits can be made by grooving with a numerically controlled machine.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Details Of Resistors (AREA)
  • Networks Using Active Elements (AREA)
  • Semiconductor Integrated Circuits (AREA)
  • Parts Printed On Printed Circuit Boards (AREA)
  • Apparatuses And Processes For Manufacturing Resistors (AREA)
  • Non-Adjustable Resistors (AREA)

Abstract

The invention relates to a resistive element consisting of a strip of resistive material in which slots (18, 19, 20, 21) are formed, according to a defined pitch, delimiting at least one zig-zag electrical circuit between two ends (11, 12) of the resistive element serving as electrical connections, characterised in that the said slots are inclined with respect to an axis passing through the said electrical connections by an angle with a value determined so as to confer the desired electrical resistance on the said resistive element. Application to braking rheostats. <IMAGE>

Description

La présente invention concerne un élément résistif pour résistance de puissance.The present invention relates to a resistive element for power resistance.

Certaines résistances de puissance utilisent comme partie résistive des rubans ou des plaques métalliques. C'est le cas en particulier des résistances de puissance employées en traction ferroviaire comme rhéostat de freinage. Pour limiter les échauffements et les usures des freins mécaniques, une partie importante de l'énergie cinétique de l'engin est convertie en énergie électrique dissipée sous forme thermique dans les rhéostats de puissance. Ces résistances doivent supporter les évères conditions de service rencontrées en traction ferroviaire. Ces rhéostats se présentent sous forme de caissons que l'on associe de façon à obtenir la résistance totale désirée. Chaque caisson possède une partie résistive réalisée généralement à partir d'un alliage de nickel et de chrome. La partie résistive peut être constituée de différentes façons, par exemple par des bandes pliées en zigzag et soudées bout à bout ou par des plaques connectées en série.Some power resistors use metallic strips or plates as a resistive part. This is the case in particular of the power resistors used in rail traction as a braking rheostat. To limit overheating and wear on mechanical brakes, a significant part of the kinetic energy of the machine is converted into electrical energy dissipated in thermal form in power rheostats. These resistors must withstand the harsh service conditions encountered in rail traction. These rheostats are in the form of boxes which are combined to obtain the desired total resistance. Each box has a resistive part generally made from an alloy of nickel and chromium. The resistive part can be constituted in different ways, for example by strips folded in a zigzag and welded end to end or by plates connected in series.

Il existe, selon l'art connu, plusieurs possibilités pour réaliser la partie résistive de la résistance de puissance. Elle peut consister en un ruban dimensionné, dès la fabrication, en largeur, épaisseur et longueur. La résistivité est définie à la coulée, le laminage détermine son épaisseur, le coupage sa largeur et le débit sa longueur. Cette méthode présente plusieurs inconvénients. Le temps d'approvisionnement est long (quatre ou cinq mois) puisque les interventions se déroulent à partie de la coulée du métal. Le coût de fabrication est élevé puisque les pièces sont faites à la demande.According to the prior art, there are several possibilities for producing the resistive part of the power resistor. It can consist of a dimensioned ribbon, from the manufacturing, in width, thickness and length. The resistivity is defined during casting, the rolling determines its thickness, the cutting its width and the flow its length. This method has several drawbacks. The supply time is long (four or five months) since the interventions take place from the metal casting. The manufacturing cost is high since the parts are made on demand.

Une autre solution connue est de réaliser les parties résistives en métal déployé. Ceci permet de conférer la résistance voulue à une bande métallique. La technique utilisée à cette occasion (perçage de fentes, étirement du métal) a pour conséquence d'écrouir le métal, de l'abîmer et de le fissurer. Il en résulte des différences locales de résistance et un comportement inhomogène aux dilatations thermique.Another known solution is to produce the resistive parts made of expanded metal. This provides the desired resistance to a metal strip. The technique used on this occasion (drilling of slits, stretching of the metal) has the effect of hardening the metal, damaging it and to crack it. This results in local differences in resistance and inhomogeneous behavior to thermal expansion.

On connaît d'autre part des plaques résistives commercialisées par la société française RESISTEL S.A. et qui possèdent des fentes toujours perpendiculaires la longueur des plaques (voir figure 1). La valeur de la résistance est fonction du pas imposé aux fentes transversales. Cette solution s'avère beaucoup plus satisfaisante que les précédentes : il n'y a pas d'altération locale de résistance, les fentes pouvant être effectuées sans malmener le métal. Le pas des fentes permettant l'ajustement de la résistance, les variations d'épaisseur et de résistivité de plaques d'origines différentes peuvent ainsi être compensées. Cependant, il s'avère impossible par ces fentes transversales de donner aux plaques résistives des valeurs très précises.We also know resistive plates sold by the French company RESISTEL S.A. and which have slots always perpendicular to the length of the plates (see Figure 1). The resistance value is a function of the pitch imposed on the transverse slots. This solution turns out to be much more satisfactory than the previous ones: there is no local alteration in resistance, the slits being able to be made without roughing up the metal. The pitch of the slots allowing the resistance to be adjusted, the variations in thickness and resistivity of plates of different origins can thus be compensated. However, it proves impossible by these transverse slots to give the resistive plates very precise values.

L'invention permet de remédier à ces inconvénients. On propose un élément résistif, en forme de plaque ou de ruban, dont plusieurs peuvent être associés pour constituer une résistance de puissance, cet élément résistif possédant des fentes inclinées selon un angle déterminé. L'angle d'inclinaison des fentes et le pas de ces fentes permet d'ajuster finement la valeur de la résistance de l'élément résistif (jusqu'au centième d'ohm).The invention overcomes these drawbacks. A resistive element is proposed, in the form of a plate or ribbon, several of which can be combined to constitute a power resistance, this resistive element having slots inclined at a determined angle. The angle of inclination of the slots and the pitch of these slots makes it possible to finely adjust the value of the resistance of the resistive element (up to a hundredth of an ohm).

L'invention a donc pour objet un élément résistif constitué par une bande en matériau résistif dans laquelle sont pratiquées, selon un pas déterminé, des fentes délimitant au moins un circuit électrique en zigzag entre deux extrémités de l'élément résistif servant de connexions électriques, caractérisé en ce que lesdites fentes sont inclinées, par rapport à un axe passant par lesdites connexions électriques, d'un angle de valeur déterminée pour conférer audit élément résistif la résistance électrique désirée.The subject of the invention is therefore a resistive element constituted by a strip of resistive material in which are made, according to a determined pitch, slots delimiting at least one zigzag electrical circuit between two ends of the resistive element serving as electrical connections, characterized in that said slots are inclined, with respect to an axis passing through said electrical connections, by an angle of determined value to give said resistive element the desired electrical resistance.

La bande peut avantageusement avoir la forme d'une plaque.The strip can advantageously have the form of a plate.

L'élément résistif peut comporter plusieurs circuits électriques réunis en parallèle par lesdites extrémités. Ceci présente l'avantage de conférer une grande souplesse dans l'ajustement de la résistance. On peut dans ce cas agir sur le pas des fentes, leur angle d'inclinaison et le nombre de circuits électriques.The resistive element may comprise several electrical circuits joined in parallel by said ends. This has the advantage of giving great flexibility in adjusting the resistance. In this case, one can act on the pitch of the slots, their angle of inclination and the number of electrical circuits.

Les circuits électriques peuvent être délimités par des fentes pratiquées à partir des bords de la bande joignant lesdites extrémités et par des fentes internes pratiquées à l'intérieur de la bande.The electrical circuits can be delimited by slots made from the edges of the strip joining said ends and by internal slots made inside the strip.

Dans ce cas, une fente supplémentaire peut être avantageusement prévue entre l'extrémité d'un circuit électrique et l'extrémité correspondante de l'élément résistif si cette extrémité de circuit électrique est comprise entre une fente interne et l'un desdits bords de la bande.In this case, an additional slot may advantageously be provided between the end of an electrical circuit and the corresponding end of the resistive element if this end of the electrical circuit is between an internal slot and one of said edges of the bandaged.

Ceci contribue à une meilleure distribution du courant dans les circuits électriques de l'élément résistif et évite les surchauffes locales.This contributes to a better distribution of the current in the electrical circuits of the resistive element and avoids local overheating.

L'élément résistif peut comporter en série plusieurs circuits électriques en parallèle.The resistive element can comprise in series several electrical circuits in parallel.

L'invention sera mieux comprise et d'autres avantages et particularités apparaîtront à la lecture de la description qui va suivre, donnée à titre d'exemple non limitatif, accompagnée des dessins annexés parmi lesquels :

  • la figure 1 représente une plaque résistive selon l'art connu,
  • la figure 2 représente une première variante de plaque résistive selon l'invention;,
  • la figure 3 est un diagramme explicatif,
  • la figure 4 représente une seconde variante de plaque résistive selon l'invention.
The invention will be better understood and other advantages and features will appear on reading the description which follows, given by way of nonlimiting example, accompanied by the appended drawings among which:
  • FIG. 1 represents a resistive plate according to the known art,
  • FIG. 2 represents a first variant of a resistive plate according to the invention;
  • FIG. 3 is an explanatory diagram,
  • FIG. 4 represents a second variant of the resistive plate according to the invention.

La figure 1 représente, vue de dessus, une plaque résistive selon l'art connu. La plaque rectangulaire 1, en alliage de nickel et de chrome, comporte deux extrémités opposées 2 et 3 par lesquelles la plaque sera fixée dans un rhéostat comprenant une pluralité de plaques identiques. Ces extrémités 2 et 3 servent aussi de connexions électriques pour la mise en série des différentes plaques résistives du rhéostat selon une méthode bien connue de l'homme du métier. Des trous 4 et 5 percés en position médiane dans les extrémités 2 et 3 peuvent assurer à la fois le maintien mécanique des plaques et leur mise en série.FIG. 1 represents, seen from above, a resistive plate according to the known art. The rectangular plate 1, in alloy of nickel and chromium, has two opposite ends 2 and 3 by which the plate will be fixed in a rheostat comprising a plurality of identical plates. These ends 2 and 3 also serve as electrical connections for placing the various resistive plates of the rheostat in series according to a method well known to those skilled in the art. Holes 4 and 5 drilled in the middle position in the ends 2 and 3 can ensure both the mechanical maintenance of the plates and their placing in series.

Des fentes sont pratiquées dans la plaque à partir des bords 6 et 7 joignant les extrémités 2 et 3 : des fentes 8 réalisées à partir du bord 6 et des fentes 9 réalisées à partir du bord 7. Les fentes 8 et 9 sont situées en alternance de manière à réaliser entre les extrémités 2 et 3 un circuit électrique en zigzag.Slots are made in the plate from the edges 6 and 7 joining the ends 2 and 3: slots 8 made from the edge 6 and slots 9 made from the edge 7. The slots 8 and 9 are located alternately so as to form a zigzag electrical circuit between the ends 2 and 3.

Les fentes 8 et 9 sont perpendiculaires aux bords 6 et 7 de la plaque résistive 1 et sont donc perpendiculaires à un axe passant par les trous 4 et 5.The slots 8 and 9 are perpendicular to the edges 6 and 7 of the resistive plate 1 and are therefore perpendicular to an axis passing through the holes 4 and 5.

La valeur de la résistance de la plaque 1 s'ajuste en jouant sur le pas des fentes 8 et 9 régulièrement espacées. La plaque comportant une pluralité de fentes, il est difficile à partir d'une seule variable d'ajuster avec précision la valeur de sa résistance. Cette difficulté augmente avec le nombre de fentes.The value of the resistance of the plate 1 is adjusted by adjusting the pitch of the regularly spaced slots 8 and 9. Since the plate has a plurality of slots, it is difficult from a single variable to precisely adjust the value of its resistance. This difficulty increases with the number of slots.

La figure 2 est une vue de dessus d'une plaque résistive 10 selon l'invention. C'est une plaque rectangulaire, par exemple en nickel-chrome, qui comporte deux extrémités opposées 11 et 12. Des trous 13 et 14 percés dans ces extrémités servent à la fixation mécanique de la plaque 10 ainsi qu'à son raccordement électrique. Un trou supplémentaire 15 en partie centrale permet d'assurer un maintien mécanique intermédiaire du même type que pour les extrémités.Figure 2 is a top view of a resistive plate 10 according to the invention. It is a rectangular plate, for example made of nickel-chrome, which has two opposite ends 11 and 12. Holes 13 and 14 drilled in these ends serve for the mechanical fixing of the plate 10 as well as for its electrical connection. An additional hole 15 in the central part ensures intermediate mechanical support of the same type as for the ends.

Les bords 16 et 17 de la plaque 10 joignent les extrémités 11 et 12. A partir du bord 16 on a pratiqué des fentes 18. A partir du bord 17 on a pratiqué des fentes 19. L'intérieur de la plaque 10 comporte une série de fentes 20 dans sa partie supérieure, selon la vue de la figure 2. Il comporte également une série de fentes 21 dans sa partie inférieure.The edges 16 and 17 of the plate 10 join the ends 11 and 12. From the edge 16, slots were made 18. From the edge 17, slots 19 were made. The interior of the plate 10 has a series of slots 20 in its upper part, according to the view in FIG. 2. It also has a series of slots 21 in its lower part.

Les fentes délimitent trois circuits électriques en parallèle dans la partie gauche de la plaque et trois circuits électriques en parallèle dans la partie droite. L'un de ces circuits est figuré en traits pointillés. La plaque 10 comporte donc en série deux ensembles comprenant chacun trois circuits électriques en parallèle.The slots delimit three electrical circuits in parallel on the left side of the plate and three electrical circuits in parallel on the right side. One of these circuits is shown in dotted lines. The plate 10 therefore comprises in series two assemblies each comprising three electrical circuits in parallel.

Pour permettre une dissipation thermique uniforme, il est très avantageux de rendre les circuits électriques indentiques entre eux. Pour cette raison, les fentes internes 20 et 21 ont toutes la même longueur et les fentes 18 et 19 des bords de plaque sont de longueur moitié. Le pas entre deux fentes successives est le même pour toute la plaque et l'angle d'inclinaison est bien sûr toujours le même.To allow uniform heat dissipation, it is very advantageous to make the electrical circuits identical to each other. For this reason, the internal slots 20 and 21 are all the same length and the slots 18 and 19 of the plate edges are half length. The pitch between two successive slots is the same for the entire plate and the angle of inclination is of course always the same.

On constate que les extrémités des circuits électriques en parallèle sont alignées pour chaque ensemble de trois circuits.It can be seen that the ends of the electrical circuits in parallel are aligned for each set of three circuits.

Les fentes 18, 19, 20 et 21 sont inclinées du même angle ϑ par rapport à l'axe longitudinal de la plaque.The slots 18, 19, 20 and 21 are inclined at the same angle ϑ relative to the longitudinal axis of the plate.

La résistance de la plaque dépend de ses caractéristiques propres (résistivité, dimensions), du nombre de ses circuits électriques, du pas des fentes et également de l'angle d'inclinaison de ces fentes.The resistance of the plate depends on its own characteristics (resistivity, dimensions), the number of its electrical circuits, the pitch of the slots and also the angle of inclination of these slots.

La figure 3 montre la plage d'évolution de la résistance R de la plaque 10 en fonction de l'angle d'inclinaison ϑ pour des valeurs comprises entre 45 et 80° et en fonction des dimensions de la plaque, du pas des fentes et du nombre de circuits électriques. L'axe des ordonnées est gradué en valeurs relatives. Pour la courbe supérieure délimitant la plage, on constate que pour des valeurs d'angle se rapprochant de 45°, la variation de résistance est faible. Pour des valeurs se rapprochant de 80°, la variation de résistance est importante. La plage située entre 60 et 70° est intéressante parce qu'elle permet un bon contrôle de la variation de résistance en fonction de l'angle d'inclinaison. Sur la figure 2, les fentes sont inclinées d'environ 66°.FIG. 3 shows the range of evolution of the resistance R of the plate 10 as a function of the angle of inclination ϑ for values between 45 and 80 ° and as a function of the dimensions of the plate, the pitch of the slots and the number of electrical circuits. The ordinate axis is graduated in relative values. For the upper curve delimiting the range, it can be seen that for angle values approaching 45 °, the variation in resistance is small. For values approaching 80 °, the resistance variation is significant. The range between 60 and 70 ° is interesting because it allows good control of the resistance variation as a function of the angle of inclination. In Figure 2, the slots are inclined by about 66 °.

Aux essais de la plaque représentée à la figure 2 on a cependant constaté la présence de zones plus chaudes qu'ailleurs. Ces zones sont celles portant la référence 22. Elles correspondent à une extrémité de circuit électrique comprise entre une fente interne et un bord latéral de la plaque.When testing the plate shown in Figure 2, however, we found the presence of hotter areas than elsewhere. These areas are those bearing the reference 22. They correspond to one end of the electrical circuit between an internal slot and a lateral edge of the plate.

Le remède pour éviter l'apparition de zones trop chaudes consiste à prévoir une fente supplémentaire entre l'extrémité du circuit électrique en question et l'extrémité correspondante de l'élément résistif. C'est ce que montre la figure 4 où l'on a représenté une plaque résistive 25, du type de la figure 2, mais comportant ces fentes supplémentaires référencées 26, de même pas et de même largeur que les autres.The remedy for avoiding the appearance of excessively hot zones consists in providing an additional slit between the end of the electrical circuit in question and the corresponding end of the resistive element. This is shown in Figure 4 where there is shown a resistive plate 25, of the type of Figure 2, but having these additional slots referenced 26, of the same pitch and the same width as the others.

Les fentes peuvent être effectéées par rainurage avec une machine à commande numérique.The slits can be made by grooving with a numerically controlled machine.

Claims (6)

1 - Elément résistif constitué par une bande en matériau résistif dans laquelle sont pratiquées, selon un pas déterminé, des fentes (18, 19, 20, 21) délimitant au moins un circuit électrique en zigzag entre deux extrémités (11, 12) de l'élément résistif servant de connexions électriques, lesdites fentes étant inclinées, par rapport à un axe passant par lesdites connexions électriques, d'un angle de valeur éterminée pour conférer audit élément résistif la résistance électrique désirée; caractérisé en ce que l'élément résistif comporte: - une série de fentes (18) pratiquée à partir du bord (16) de la plaque (10); - une série de fentes (19) pratiquée à partir du bord (17) de la plaque (10); et - au moins une série de fentes (20, 21) pratiquées à l'intérieur de la plaque (10); de manière à délimiter au moins deux circuits électriques en parrallèle. 1 - Resistive element constituted by a strip of resistive material in which are made, according to a determined pitch, slots (18, 19, 20, 21) delimiting at least one electrical circuit in zigzag between two ends (11, 12) of the resistive element serving as electrical connections, said slots being inclined, with respect to an axis passing through said electrical connections, by an angle of determined value to give said resistive element the desired electrical resistance; characterized in that the resistive element comprises: - a series of slots (18) made from the edge (16) of the plate (10); - A series of slots (19) made from the edge (17) of the plate (10); and - at least one series of slots (20, 21) made inside the plate (10); so as to delimit at least two electrical circuits in parallel. 2 - Elément résistif selon la revendication 1, caractérisé en ce que la bande forme une plaque (10, 25). 2 - Resistive element according to claim 1, characterized in that the strip forms a plate (10, 25). 3 - Elément résistif selon l'une des revendications 1 ou 2, caractérisé en ce qu'elle comporte plusieurs circuits électriques réunis en parallèle par lesdites extrémités. 3 - resistive element according to one of claims 1 or 2, characterized in that it comprises several electrical circuits joined in parallel by said ends. 4 - Elément selon la revendication 3, caractérisé en ce que les circuits électriques sont délimités par des fentes (18, 19) pratiquées à partir des bords (16, 17) de la bande joignant lesdites extrémités (11, 12) et par des fentes internes (20, 21) pratiquées à l'intérieur de la bande. 4 - Element according to claim 3, characterized in that the electrical circuits are delimited by slots (18, 19) formed from the edges (16, 17) of the strip joining said ends (11, 12) and by slots internal (20, 21) formed inside the strip. 5 - Elément résistif selon la revendication 4, caractérisé en ce qu'une fente supplémentaire (26) est prévue entre l'extrémité d'un circuit électrique et l'extrémité correspondante de l'élément résistif si cette extrémité de circuit électrique est comprise entre une fente interne et l'un desdits bords de la bande. 5 - resistive element according to claim 4, characterized in that an additional slot (26) is provided between the end of an electrical circuit and the corresponding end of the resistive element if this end of the electrical circuit is between an internal slot and one of said edges of the strip. 6 - Elément résistif selon l'une quelconque des revendications 3 à 5, caractérisé en ce qu'il comporte en série plusieurs circuits électriques en parallèle. 6 - resistive element according to any one of claims 3 to 5, characterized in that it comprises in series several electrical circuits in parallel.
EP94400913A 1993-04-30 1994-04-27 Resistive element for power resistor Expired - Lifetime EP0622813B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9305166 1993-04-30
FR9305166A FR2704683B1 (en) 1993-04-30 1993-04-30 Resistive element for power resistance.

Publications (2)

Publication Number Publication Date
EP0622813A1 true EP0622813A1 (en) 1994-11-02
EP0622813B1 EP0622813B1 (en) 1997-07-09

Family

ID=9446635

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94400913A Expired - Lifetime EP0622813B1 (en) 1993-04-30 1994-04-27 Resistive element for power resistor

Country Status (6)

Country Link
EP (1) EP0622813B1 (en)
KR (1) KR100297480B1 (en)
AT (1) ATE155278T1 (en)
DE (1) DE69404078T2 (en)
ES (1) ES2103549T3 (en)
FR (1) FR2704683B1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2468677A (en) * 2009-03-17 2010-09-22 Eltek Valere As Resistor device
CN105702400A (en) * 2016-03-31 2016-06-22 湖南福德电气有限公司 Direct current component resistor applicable to large current limiting

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100979141B1 (en) 2008-05-27 2010-08-31 주식회사 푸름 Breaking resistor unit for crane
KR100971463B1 (en) 2008-06-02 2010-07-22 주식회사 푸름 Breaking resistor unit for railroad car
CN218788734U (en) 2019-12-18 2023-04-04 米沃奇电动工具公司 Power tool and brake system for power tool

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB196480A (en) * 1922-05-01 1923-04-26 Robert Frederick Baerlocher Improvements in electrical resistance grids
DE420027C (en) * 1925-10-15 Hans Oberlaender Electrical resistance element
DE486243C (en) * 1929-11-14 Aeg Cast iron electrical resistance

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE420027C (en) * 1925-10-15 Hans Oberlaender Electrical resistance element
DE486243C (en) * 1929-11-14 Aeg Cast iron electrical resistance
GB196480A (en) * 1922-05-01 1923-04-26 Robert Frederick Baerlocher Improvements in electrical resistance grids

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2468677A (en) * 2009-03-17 2010-09-22 Eltek Valere As Resistor device
CN105702400A (en) * 2016-03-31 2016-06-22 湖南福德电气有限公司 Direct current component resistor applicable to large current limiting

Also Published As

Publication number Publication date
DE69404078T2 (en) 1997-10-30
ES2103549T3 (en) 1997-09-16
EP0622813B1 (en) 1997-07-09
ATE155278T1 (en) 1997-07-15
FR2704683A1 (en) 1994-11-04
DE69404078D1 (en) 1997-08-14
KR100297480B1 (en) 2001-10-24
FR2704683B1 (en) 1995-06-02

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