DE102020110554A1 - Electrical capacitor with an, in particular cylindrical, capacitor can - Google Patents

Abstract

The invention relates to an electrical capacitor with an, in particular cylindrical, capacitor can, consisting of a can jacket and a can base, at least two capacitor coils with base insulation used stacked in the capacitor can, an insulating cap on the terminal side, a multi-pole connection terminal and a cover which closes the capacitor can in a pressure-tight manner, the Capacitor windings are interconnected with each other and with the connection terminal via busbars or strip conductors with low inductance. According to the invention, the floor insulation is designed as a disk with a plurality of spring tongues extending radially from the disk center, the spring tongues having an overbend convex shape in the direction of the capacitor winding for tolerance-compensating capacitor winding guidance.

Description

The invention relates to a capacitor with an, in particular cylindrical, capacitor can, consisting of a can jacket and a can base, at least two capacitor coils with base insulation, stacked in the capacitor can, an insulating cap on the terminal side, a multi-pole connection terminal and a cover which closes the capacitor can in a pressure-tight manner, the Capacitor windings are interconnected with one another and with the connection terminal via busbars or strip conductors with low inductance, according to the preamble of claim 1.

From the DE 10 2017 119 209 A1 a lid closure for wound capacitors that can be arranged in a cup is known.

According to the object there, a further developed cover closure with at least one electrical connection fitting is to be specified which, on the one hand, enables the assembly of different coil internals using prefabricated standard covers and, on the other hand, allows separate potting to be dispensed with.

The cover closure should have a low self-inductance and large air and creepage distances with a small installation space and, moreover, be designed to be gas-tight.

The previously known solution is based on a lid closure for wound capacitors arranged in a cup, which accommodates at least one electrical connection fitting. This is designed as an insulated cover duct. Furthermore, the cover closure consists of a plate-shaped plastic part to which the connection fitting is attached.

Starting from the plate-shaped plastic part, a molded centering pin extends on its underside in the direction of the capacitor winding.

This centering pin engages in the winding core and thereby secures the position of the winding in relation to the capacitor can and also with regard to the lid closure.

Furthermore, the underside of the plate-shaped plastic part has a plurality of flexible, tongue-like, spring-elastic properties having arc-shaped elements which serve to fix the respective capacitor winding in a way that compensates for tolerances.

In the assembled state, the undersides of the respective arcuate elements lie against one of the end faces of the relevant capacitor winding, so that it is also secured in relation to the longitudinal axis direction of the cup.

The arch-shaped elements, which have resilient properties, allow for height compensation, in particular taking manufacturing tolerances into account.

The tongues are segment-like and run from the edge of the plate-shaped plastic part in the direction of the centering pin, but without coming into contact with the centering pin.

The underside of the terminal is designed as a screw connection and can be connected to a switch rail with a material fit but also with a force fit. The known lid closure with plastic part, centering pin and tongue-like, resilient properties exhibiting arcuate elements has great advantages with regard to the desired fixation of the winding and tolerance compensation compared to the prior art known to date.

However, problems arise when more than two connection terminals are necessary in addition to the contacting to the capacitor windings that is then required for high-current and particularly low-inductance embodiments. The installation space on the underside of the cover is limited by the design of the spring tongues, which leads to a complicated guidance of the switching strips or busbars required for the electrical connection.

From the DE 10 2005 018 339 A1 an arrangement with a capacitor module and a method for its operation is previously known. In order to achieve particularly safe operation of such an arrangement, it is proposed that the arrangement have a safety device connected to the at least one capacitor, which monitors the operating state of the capacitor or the capacitor module and switches to a safety operating mode in the event of an operating state recognized as unsafe .

The safety device has a spatial expansion of the at least one capacitor or the expansion measuring device measuring the spatial expansion of the capacitor module and is designed in such a way that the safety operating mode starts when a predetermined maximum expansion measurement is exceeded. The strain gauges in question are implemented in such a way that they completely encompass the capacitor housing.

When setting up according to DE 10 2008 062 656 A1 , which comprises a capacitor module, it is proposed that a die The housing accommodating the capacitor cells of the capacitor module is provided, the housing having a capacitor chamber which accommodates the capacitor cells and is sealed in a pressure-tight manner. An internal pressure of the capacitor chamber is detected by a pressure sensor to determine whether one of the capacitor cells is damaged.

In the case of the capacitor with protective device, see DE 10 2015 215 729 A1 it is proposed to detect a fault condition that the capacitor has such a tight housing that the volume of the housing changes in the event of a fault, the change in the volume of the housing being detectable by a protective device.

For this purpose, a disengageable volume is integrated into the capacitor housing through structural measures. This integration takes place through shaping. The shape of the capacitor housing is designed in such a way that an increase in pressure in the interior of the capacitor causes the housing to increase in volume.

Embossing, beads, expansion joints or corrugated pipes should be suitable for this. The integration can also be carried out through the material properties of the housing. In this regard, the housing is formed by a material with such a material property that when the pressure inside the capacitor increases, the volume of the housing increases.

In order to generate a change in volume with increasing pressure inside the condenser, different material thicknesses or strengths in the construction of the condenser should be particularly suitable. As is known, there are two fundamentally problematic scenarios in the case of film capacitors with a dielectric made of plastic. A first problem is the failure due to low impedance, i.e. due to a short circuit. A short circuit can be controlled with the usual protective functions, in the simplest case a fuse.

A so-called high impedance case is more problematic, due to aging processes. This can lead to increasing electricity heat losses in the condenser. As a result of the rise in temperature, plastic parts of the capacitor can melt and pyrolysis processes can take place. This creates gases. For the above reason, typical cup capacitors are designed to be pressure-tight, in particular gas-tight, in order to prevent escaping gases from forming an explosive mixture in conjunction with oxygen.

In order to secure the capacitor in the event of such a fault, which leads to an increase in pressure, so-called overpressure tear-off safeguards are used. When gas is formed inside the capacitor cup, these lead to a movement of the connections of the capacitor, so that the tear-off protection is triggered. This means that the capacitor can be separated from its voltage source.

Another possibility for recognizing the onset of gas formation is to detect the internal pressure of the condenser, as already described above.

Overpressure switches or corresponding sensors in the interior of the capacitor, however, lead to impedance problems, as in the case of tear-off safeguards located inside, and to production-side expenditure with higher costs.

From the above, it is therefore the object of the invention to provide a further developed capacitor with a, in particular, cylindrical capacitor can, which is designed with multiple poles, i.e. has at least four or more connection terminals, whereby a particularly low-inductance connection of the capacitor winding of the capacitor to the connection terminals is to be created .

In addition, the capacitor should be designed in such a way that an overpressure in the capacitor can be detected particularly easily with an external sensor system or an external switching device and can be used to evaluate error states or to switch off. The capacitor cup should be designed in such a way that the position of the capacitor coil in the cup and thus the related connectors, connecting parts, tapes or similar means does not change even if the pressure rises, so that a defined impedance-side state is maintained in any case.

The object of the invention is achieved with an electrical capacitor according to the teaching of claim 1, with claim 2 being based on the particular embodiment of the design of the capacitor can for the purpose of sensory detection of an increasing internal pressure in the can.

The further subclaims include at least useful refinements and developments of the electrical capacitor.

Accordingly, an electrical capacitor with a, in particular cylindrical, capacitor can is assumed, which in turn consists of a can jacket and a can bottom.

Furthermore, at least two are stacked in the capacitor can Capacitor winding present. Floor insulation is also provided. An insulating cap on the terminal side secures the upper roll. Furthermore, there is a multi-pole connection terminal and a cover is formed which closes the capacitor in a pressure-tight manner, the capacitor windings being connected to one another and to the connection terminal in a low-inductive manner via busbars or strip conductors.

According to a first relevant embodiment, the bottom insulation of the electrical capacitor is designed as a disk with a plurality of spring tongues extending radially from the disk center, the spring tongues having an arched, convex shape in the direction of the capacitor winding, which is used to guide the capacitor winding to compensate for tolerances.

The overbend, convex shape of the spring tongues is designed in such a way that the corresponding underside of the roll is touched in the radially outer area of the roll. In addition to the resiliently elastic guidance of the winding arrangement in the capacitor can, the disk with its spring tongues has insulating properties and thus serves to isolate the capacitor winding arrangement at a distance from the usually metallic can and thus also the metallic capacitor can base.

In a further development of the invention, the cylindrical capacitor can is based on a can shell known per se and a can bottom which is usually formed in one piece or integrally.

In the inner transition area between the cup shell and the cup base, an edge reinforcement is formed on the circumference and directed towards the inside of the cup, the top side of which forms a support surface in order to keep the rest of the cup base free of mechanical load.

The edge reinforcement has interruptions, notches, slots, incisions or gaps or the like over its inner circumferential course, which run in the direction of the cup base.

These interruptions do not lead to a mechanical weakening of the base, but merely serve to equalize the pressure inside a capacitor implemented on the basis of the described beaker.

The edge reinforcement directed towards the inside of the cup serves to support the above-described floor insulation, designed as a disk, with a large number of spring tongues extending radially towards the center of the disk.

Accordingly, the floor insulation is supported as a disk with the capacitor winding on the contact surface and the interruptions bring about the desired pressure equalization over the entire volume of the inside of the cup.

When the internal pressure in the cup increases, the bottom of the cup is subject to deformation, which can be detected with a sensor system that can be arranged on the outside of the capacitor.

In one embodiment, the interruptions in the edge reinforcement run uniformly distributed on the inner circumference.

The support surface of the edge reinforcement is essentially designed as a flat surface and in this respect corresponds to the underside of the floor insulation.

The bottom insulation can also have a circumferential bevel on its underside, so that there is no undesired covering of the pressure equalization channels in the form of the aforementioned interruptions.

The aforementioned sensor system is designed, for example, as a switching device which is irreversible in relation to its switching state and which is in operative connection with the outside of the floor.

The sensor system can, however, also be an optical scanning device that responds to a deformation of the bottom of the cup.

In the unpressurized state, the bottom of the cup has an inner curvature and is therefore concave. As the pressure rises, the bottom of the cup deforms in a convex direction, that is, in the sense of an outer curvature that can be scanned accordingly.

The deformation of the bottom of the cup in the convex direction can in this respect be detected with a simple button, with a safety circuit being able to be triggered via the button.

If a larger number of capacitors of the design according to the invention are arranged in an electrical device, the corresponding sensor system, in particular the mentioned switch or button, can continue to be used after a defective capacitor has been replaced.

According to a further embodiment of the invention, an insulating insert with bushings for the connection terminals is formed in the cover of the capacitor, the underside of the cover receiving an insulating disk and switching strips that are in contact with the connection terminals are arranged on the insulating disk. There are also between the switching strips insulating separating webs, preferably as components of the insulating insert located in the cover.

Some of the switching bands are bent in order to contact a capacitor winding close to the cover.

Another part of the switch bands has soldering surfaces for connecting switch band extensions. The switching band extensions are isolated in the space between the inner wall of the cup and the outer surface of the respective capacitor winding. Depending on the number of capacitor windings, the number of terminals and the desired external interconnection, a large number of flat switching strips in a low-inductance embodiment can be arranged at a distance in the circumferential space within the cup. Since the cover area is free of spring tongues, and these spring tongues have been relocated to the base area of the cup in the form of floor insulation, there is sufficient installation space for the low-inductance coupling of the switching strips to the connection terminals in the cover.

The sealing of the cover with respect to or with respect to the condenser can takes place in a known manner by material connection, by the arrangement of sealing means, by crimping or the like or by a combination of the aforementioned measures.

The terminal-side insulating cap surrounds an upper capacitor winding section, the insulating cap having a centering pin which engages in an opening at the end of a capacitor winding tube and thus effects a corresponding centering. Where necessary, the capacitor windings also have jacket insulation in order to exclude short circuits, in particular to switching strips or the inside of the cup.

On the underside of the cup there can be extensions designed as means for fastening the capacitor to the housing of a carrier device or the like.

The invention will be explained in more detail below on the basis of exemplary embodiments and with the aid of figures.

• 1 einen Längsschnitt durch einen erfindungsgemäßen zylindrischen Kondensatorbecher mit nach innen gerichteter, gewölbter Randverstärkung;
• 2 eine Draufsicht in Richtung Innenseite eines Kondensatorbechers mit der Schnittlinie A-A zur Definition des Schnittes gemäß 1;
• 3 einen Längsschnitt durch einen elektrischen Kondensator mit Kondensatorbecher und dort erkennbarem bekanntem Kondensatordeckel, Anschlussterminal, Innenverdrahtung und Bodenisolierung;
• 4 eine Detaildarstellung des unteren Endes des Kondensators gemäß 3 mit Bodenisolierkappe, Wickel, Becherboden und Ra ndverstä rkung;
• 5 und 6 beispielhafte Darstellungen der Verformung des Becherbodens im Ergebnis einer Druckeinwirkung von konkav (druckfrei) gemäß 5 bis zu konvex (druckbelastet) nach 6, wobei die unteren Darstellungen in den 5 und 6 die Schnittverläufe A-A zur Definition der Ansichten in den oberen Darstellungen repräsentieren;
• 7 eine Längsschnittdarstellung durch den erfindungsgemäßen elektrischen Kondensator mit Bodenisolierung in Form einer Scheibe mit einer Vielzahl von sich vom Scheibenzentrum radial erstreckenden Federzungen;
• 8 eine beispielhafte Draufsicht auf einen Deckel des erfindungsgemäßen Kondensators mit vierpoligen Anschlussklemmen bzw. Terminals;
• 9 eine Ansicht auf die Unterseite des Deckels gemäß 8 mit mit den Anschlussterminals vernieteten Schaltbändern, welche Lötflächen aufweisen;
• 10 eine Darstellung der Unterseite des Deckels mit angelöteten Schaltbandverlängerungen;
• 11 eine Darstellung ähnlich derjenigen nach 10, jedoch mit bereits angesetzter oberer Isolierkappe;
• 12 eine Explosivdarstellung des Kondensators mit Wickelpaket, Mantelisolation, Bodenisolierung und umhüllendem Kondensatorbecher;
• 13 eine perspektivische Darstellung eines beispielhaften fertigen Kondensators;
• 14 und 15 eine beispielhafte Ausbildung vierpoliger Anschlussterminals mit Mitteln zur Stickstofffüllung und Abdeckkappe hierfür; und
• 16 und 17 eine weitere Variante der Ausführung der Anschlussterminals mit entsprechender Isolierung, Möglichkeit zur Stickstofffüllung und Anordnung einer Abdeckkappe im Bereich des Zuganges zur Stickstofffüllung.

Here show:

• 1 a longitudinal section through a cylindrical capacitor can according to the invention with inwardly directed, curved edge reinforcement;
• 2 a plan view in the direction of the inside of a capacitor can with the section line AA to define the section according to 1 ;
• 3 a longitudinal section through an electrical capacitor with capacitor can and recognizable there known capacitor cover, connection terminal, internal wiring and floor insulation;
• 4th a detailed representation of the lower end of the capacitor according to 3 with base insulating cap, wrap, cup base and rim reinforcement;
• 5 and 6th exemplary representations of the deformation of the cup base as a result of a pressure effect of concave (pressure-free) according to FIG 5 up to convex (pressure loaded) after 6th , with the illustrations below in the 5 and 6th represent the sections AA for defining the views in the representations above;
• 7th a longitudinal sectional view through the electrical capacitor according to the invention with bottom insulation in the form of a disk with a plurality of spring tongues extending radially from the disk center;
• 8th an exemplary plan view of a cover of the capacitor according to the invention with four-pole connection terminals or terminals;
• 9 a view of the underside of the lid according to 8th with switching strips riveted to the connection terminals, which have soldering surfaces;
• 10 a representation of the underside of the cover with soldered switch band extensions;
• 11 a representation similar to that after 10 , but with the upper insulating cap already attached;
• 12th an exploded view of the capacitor with winding package, jacket insulation, floor insulation and surrounding capacitor cup;
• 13th a perspective view of an exemplary finished capacitor;
• 14th and 15th an exemplary design of four-pole connection terminals with means for nitrogen filling and a cover cap therefor; and
• 16 and 17th Another variant of the design of the connection terminals with appropriate insulation, the possibility of nitrogen filling and the arrangement of a cover cap in the area of the access to the nitrogen filling.

The capacitor is of a cylindrical design with a beaker jacket 1 and a cup base 2 the end.

In the transition area between the cup shell 1 and cup base 2 is on the inside and to the inside of the cup 3 directed, an edge reinforcement 4th formed, the top of which has a support surface 5 forms to the rest of the cup base 2 to be kept mechanically load-free if there is a corresponding capacitor winding and floor insulation inside the capacitor can.

The edge reinforcement 4th has interruptions over its course on the inner circumference, for example in the form of notches 6th or the like, which in the direction of the cup base 2 get lost.

The bottom of the cup 2 is arched inward in the unpressurized state, that is, it shows according to the sectional view 1 a concave shape viewed from the bottom of the cup.

According to the representations 3 and 4th which show a longitudinal section through an electrical capacitor known per se with a cylindrical capacitor can, the basic structure of an electrical capacitor of the type relevant here with a new type of can bottom can now be seen.

In the condenser cup, the one made from the cup jacket 1 and cup base 2 exists, one or more electrically interconnected windings 7th used.

The outside diameter of the windings 7th is smaller than the inner diameter of the corresponding capacitor can.

At the lower end of the lower capacitor winding 7th comes a floor insulation 8th for use, which, as shown in detail in the figure, at the lower end of the winding 7th and insofar as the winding in the capacitor can bears.

One lid 11 forms a tight seal on the capacitor can. There are electrically isolated connection terminals in the cover 9 that have a wiring 10 with the respective wrap 7th are contacted.

In the transition area between the cup jacket and the cup base 2 there is also an edge reinforcement on the inside circumference and towards the inside of the cup 4th recognizable, the top of which is a support surface 5 for floor insulation 8th forms.

The notches 6th put in conjunction with a bevel on the underside of the floor insulation 8th pressure equalization across the entire cup volume.

As a result, the entire capacitor winding 7th with recourse to the floor insulation 8th on the support surface 5 of the capacitor can, the bottom of the can remains 2 mechanically load-free. The bottom of the cup 2 is only loaded with forces in the event of overpressure due to malfunction of the capacitor, as can be seen from the synopsis of the 5 and 6th can be understood.

You now arrange on the outside near the bottom of the cup 2 a switching device, for example a button, is easily activated in the event of a pressure increase due to deformation of the bottom of the cup 2 this abnormal state of the corresponding capacitor can be recognized and a switching device can be triggered and appropriate signaling based on the error state can be carried out.

From the 2 as well as the views towards the inside of the cup (lower representations according to 5 and 6th ) it is clear that there are notches or interruptions 6th the edge reinforcement 4th Extend on the inner circumference and run essentially evenly distributed.

The deformation of the bottom of the cup 2 , which is completely mechanically load-free in normal operation, is an indicator function with regard to a pressure increase in the capacitor In the case of these components, this does not lead to an undesired change in position and thus to further possible damage due to the breaking of electrical connections along with sparking and the resulting dangers.

the 7th shows a sectional view through the embodiment of an electrical capacitor with floor insulation in the form of a disk 21 with a large number of spring tongues extending radially from the disc center 20th , with the spring tongues 20th have an arched, convex shape in the direction of the capacitor winding.

The transition area between the cup shell and the cup base can be designed in the same way as on the basis of the exemplary embodiments and FIG 1 until 6th already explained.

As shown in the sectional view 7th The floor insulation can also be seen in this variant 8th as a disc 21 with a large number of spring tongues extending radially from the disc center 20th educated.

The spring tongues 20th have an arched, convex shape in the direction of the capacitor winding.

In this way, the capacitor winding is held and guided in the cup in a tolerance-compensating and insulating manner.

Between the capacitor windings 7th and the condenser can 1 is still a jacket insulation 22nd educated.

In the lid 11 is an insulating insert 23 with bushings for the connection terminals 9 formed, wherein the lid underside is an insulating washer 24 records.

On the insulating washer 24 are with the connection terminals 9 contacted switching strips 25th arranged. Between the switching bands 25th can isolate separators 26th are located.

The switching bands 25th can with the corresponding connection terminals 9 eg by riveting in places 27 be connected electrically and mechanically. In the representations according to 4th , 8th and 9 the above is illustrated using a four-pole connection terminal.

The switching bands 25th can, as for example in the 8th can be seen to have a bend in order to contact the corresponding capacitor winding close to the cover or also switching band extensions 28 (like for example 10 and 11 ) to record. A connection in this regard can be made by soldering or welding.

The switching band extensions 28 are arranged isolated in the space between the inner wall of the cup and the outer surface of the respective capacitor winding.

An insulating cap on the terminal side 29 then engages around an upper section of one of the capacitor windings 7th , as it is, for example, from the 11 is recognizable.

The insulating cap 29 still has a centering pin 30th or has a bushing for receiving a centering pin 30th on, the component of the insulating washer 24 can be, which engages in a front opening of one of the capacitor windings.

The switching bands or switching band extensions 28 provide insulation where necessary 32 to avoid short circuits, especially to the inside of the capacitor can. By bending the switching strips, they are moved into a position that creates a ready-to-install arrangement, i.e. a winding package 32 as shown in 12th shows that in this respect it is ready for installation and in addition to jacket insulation 32 and washer 21 with spring tongues in the capacitor cup 1 can be spent.

After the lid and cup have been flanged, the capacitor has a solid and tight design, as in FIG 13th shown.

the 14th until 17th show different designs of connection terminals together with insulation part 23 in each case taking into account the required separation distances.

In the embodiment according to 14th and 15th is the isolation 23 to accommodate the terminals 9 smaller area based on the overall dimensions of the lid 11 realized. In the center of the insulating part 23 there is an entrance 40 with sealing rivet for filling the capacitor with a protective gas, e.g. nitrogen. This access 40 can with a cover cap 41 be locked.

An access is analogous in this regard 40 with cap 41 in a large-area embodiment of the insulating part according to the 16 and 17th educated.

When designing the cover with a connection terminal 9 and isolator 23 there is access for a gas filling 40 outside of the isolator 23 covered or coverable area.

All in all, the design of the can capacitor according to the invention succeeds in creating a large number of low-inductance connection options in the smallest of spaces, with a tolerance-compensating positioning of the windings or winding packets in the capacitor can. The base insulation with spring tongues not only ensures the appropriate positioning of the winding package in the cup, but also provides the necessary electrical insulation to the cup, in particular to the metal cup base.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102017119209 A1 [0002]
• DE 102005018339 A1 [0014]
• DE 102008062656 A1 [0016]
• DE 102015215729 A1 [0017]

Claims (13)

Electrical capacitor with a, in particular cylindrical, capacitor can, consisting of a can jacket (1) and a can base (2), at least two capacitor coils (7) stacked in the capacitor can, a base insulation (8), an insulating cap on the terminal side, a multi-pole connection terminal (9) ) as well as a cover (11) which closes the capacitor cup pressure-tight, the capacitor windings (7) being interconnected with each other and on the connection terminal (9) via busbars or strip conductors, characterized in that the bottom insulation (8) is a washer (21) is formed with a plurality of spring tongues (20) extending radially from the disk center, the spring tongues (20) having an overbend convex shape in the direction of the capacitor winding for tolerance-compensating condenser winding guidance. Electric capacitor after Claim 1 , characterized in that in the transition area between the cup shell (1) and the cup base (2) on the inner circumference and facing the cup interior (3), an edge reinforcement (4) is formed, the top of which forms a support surface (5) around the rest of the cup base (2) mechanically load-free, the edge reinforcement (4) having interruptions, notches, slots, incisions or gaps (6) over its inner circumferential course, which run in the direction of the cup base (2), furthermore the base insulation (8) on the support surface (5) is supported, the interruptions (6) allow pressure equalization over the entire volume of the inside of the cup and the cup base (2) is subject to a deformation when the pressure inside the cup increases, which can be detected or recognized by a sensor system. Electric capacitor after Claim 2 , characterized in that the interruptions (6) of the edge reinforcement (4) run uniformly distributed on the inner circumference. Electric capacitor after Claim 2 or 3 , characterized in that the bearing surface (5) is designed essentially as a flat surface. Electrical capacitor according to one of the Claims 1 until 4th , characterized in that the bottom insulation (8) has a circumferential bevel on its underside. Electrical capacitor according to one of the Claims 2 until 5 , characterized in that the sensor system is designed as a switch which is irreversible in relation to its switching state and which is in operative connection with the bottom outside of the cup base (2). Electrical capacitor according to one of the Claims 2 until 5 , characterized in that the sensor system is designed as an optical scanning device for the cup base (2). Electrical capacitor according to one of the Claims 2 until 7th , characterized in that the cup base (2) has an inner curvature in the pressure-free state and is concave, with the cup base (2) deforming in the convex direction in the sense of an outer curvature as the pressure rises in the capacitor cup. Electric capacitor after Claim 8 , characterized in that the deformation of the cup base (2) in the convex direction is detected by a button, wherein a safety circuit can be triggered via the button. Electrical capacitor according to one of the preceding claims, characterized in that an insulated insert (23) with bushings for the connection terminals (9) is formed in the cover (11), the underside of the cover receiving an insulating washer (24) and on the insulating washer (24) switching strips (25) which are in contact with the connection terminals (9) are arranged and insulating separating webs (26) are located between the switching strips (25). Electric capacitor after Claim 10 , characterized in that some of the switching strips (25) have an angle in order to contact a capacitor winding (7) close to the cover. Electric capacitor after Claim 10 or 11 , characterized in that some of the switching strips (25) have soldering surfaces for connecting switchable extensions (28), the switchable extensions (28) being isolated in the space between the inner wall of the cup and the outer surface of the respective capacitor winding (7). Electrical capacitor according to one of the preceding claims, characterized in that the terminal-side insulating cap (29) encompasses an upper capacitor winding section, the insulating cap (29) receiving or having a centering pin (30) which is inserted into an opening (31) at the end of a capacitor winding (7 ) intervenes.

Images