EP4325536A2 - Magnetic core with protective casing - Google Patents

Abstract

A device is described below which, according to an exemplary embodiment, has a carrier which has a continuous opening along a longitudinal axis, and at least one soft magnetic tape wound around the carrier to form an annular tape core. The band is wound directly onto the carrier so that there is no play between the ring band core and the carrier. The carrier can therefore serve as part of the housing of the toroidal core.

Description

TECHNICAL FIELD

This description concerns the area of magnetic cores, inductive components and current transformers.

BACKGROUND

For the production of inductive components such as transformers, chokes, current transformers, etc., cores made of crystalline iron-based alloys such as silicon-iron, often also amorphous and nanocrystalline alloys, are used. Selection criteria for the material of the magnetic core are high permeability, low coercivity (Hc), low losses and high linearity of the hysteresis loop.

During the development of magnetic cores made of amorphous and nanocrystalline alloys, it has been shown that heat treatment in the range of 300 to 600 ° C often has to take place after core production (by winding the magnetic strip material) in order to achieve the desired magnetic properties. Heat treatment of the wound cores in an oven has been established for this purpose. After heat treatment, the mechanically sensitive cores must be protected, for example by a coating or a housing. This sequence (first winding the core, then heat treating) prevents the possibility of winding the strip material directly onto a plastic body, as the plastic would not survive the heat treatment. The usual technical plastics have a temperature resistance of around 120 to 200 °C; the heat treatment usually takes place above 400 °C.

Methods for producing magnetic cores are known, according to which an amorphous strip is heat-treated under tension and continuously through an oven in order to produce a nanocrystalline strip material, from which a magnetic core (ring strip core) is then wound. The magnetic properties of the nanocrystalline Bands can be adjusted, among other things, by controlling the tension. Such a strip material is sometimes referred to as a Zina material (Zina = tensile stress-induced anisotropy).

Such magnetic strip material already has the desired magnetic properties, so that heat treatment is no longer necessary after being wound into a magnetic core, but the strip loses its ductility during the heat treatment and becomes relatively brittle. Brittle strip material can cause problems in the production of magnetic cores because it breaks easily.

The inventors have set themselves the task of improving existing concepts for producing wound magnetic cores arranged in a housing, so that comparatively brittle materials in particular can be processed.

SUMMARY

This task is solved by the method according to claims 1 and 12 and the device according to claim 14. Various exemplary embodiments and further developments are the subject of the dependent claims.

A device is described below which, according to an exemplary embodiment, has a carrier which has a continuous opening along a longitudinal axis, and at least one soft magnetic tape wound around the carrier to form an annular tape core. The band is wound directly onto the carrier so that there is no play between the ring band core and the carrier. The carrier can therefore serve as part of the housing of the toroidal core.

Furthermore, a method for producing a toroidal strip core is described. According to an exemplary embodiment, the method comprises attaching a carrier (or a part thereof), which has a through opening along a longitudinal axis, onto a shaft; winding at least one soft magnetic tape around the carrier to form at least one toroidal tape core by rotating the shaft; and removing the carrier including the toroidal core from the shaft.

According to a further exemplary embodiment, the method comprises attaching a first part of a carrier, which has a through opening along a longitudinal axis, onto a shaft; winding a first soft magnetic tape around the first part of the carrier to form a first toroidal tape core by rotating the shaft; removing the first part of the carrier including the first toroidal core from the shaft; attaching a second part of a carrier; winding a second soft magnetic tape around the second part of the carrier to form a second toroidal tape core by rotating the shaft; removing the second part of the carrier including the second toroidal core from the shaft; and assembling the first and second parts of the carrier together with the toroidal cores wound thereon, the first and second parts of the carrier being coaxial with one another.

BRIEF DESCRIPTION OF THE DRAWINGS

• Figur 1 illustriert ein erstes Ausführungsbeispiel eines gewickelten Kerns mit Gehäuse
• Figur 2 zeigt als zweites Ausführungsbeispiel eine Modifikation des Beispiels aus Fig. 1
• Figur 3 illustriert ein drittes Ausführungsbeispiel eines gewickelten Kerns mit Gehäuse.
• Figur 4 illustriert ein viertes Ausführungsbeispiel eines gewickelten Kerns mit Gehäuse, wobei zwei Gehäuseteile mittels Snap-in-Verbindung aneinander gehalten werden.
• Figur 5 zeigt als fünftes Ausführungsbeispiel eine Modifikation des Beispiels aus Fig. 3.
• Figur 6 zeigt ein induktives Bauelement mit einem Kern gemäß Fig. 4 und einer darum gewickelten Spule.
• Figur 7 ist eine Querschnittsdarstellung durch einen gewickelten Magnetkern, dessen Ende aufgrund der Federwirkung des Bandes absteht und ein Abwickeln des Bandes durch das Gehäuse verhindert wird.
• Figur 8 zeigt einen Träger auf einer Wickelwelle in einer Ansicht in axialer Richtung.

Examples of embodiments are explained in more detail below using illustrations. The illustrations are not necessarily to scale and the exemplary embodiments are not limited to the aspects shown. Rather, emphasis is placed on presenting the principles underlying the exemplary embodiments. Shown in the pictures:

• Figure 1 illustrates a first embodiment of a wound core with housing
• Figure 2 shows a modification of the example as a second exemplary embodiment Fig. 1
• Figure 3 illustrates a third embodiment of a wound core with housing.
• Figure 4 illustrates a fourth exemplary embodiment of a wound core with a housing, with two housing parts being held together by means of a snap-in connection.
• Figure 5 shows a modification of the example as a fifth exemplary embodiment Fig. 3 .
• Figure 6 shows an inductive component with a core according to Fig. 4 and a coil wound around it.
• Figure 7 is a cross-sectional view through a wound magnetic core, the end of which protrudes due to the spring action of the band and the band is prevented from unwinding by the housing.
• Figure 8 shows a carrier on a winding shaft in a view in the axial direction.

DETAILED DESCRIPTION

The exemplary embodiments described here make it possible to produce a wound core from a soft magnetic tape after the tape has been heat treated and thus has final magnetic properties. The tape is then wound directly onto a carrier. After the core has been manufactured by winding the tape, the core remains on the carrier, which also forms part of the housing of the magnetic core. The housing is completed by at least a second housing part (outer shell), which is pushed over the magnetic core. The carrier and the outer shell are designed in such a way that they form a closed housing for the magnetic core located on the carrier. In this case, the housing can take up a smaller volume than a housing into which a core that has been heat-treated after winding is inserted, since the necessary assembly gaps are eliminated. Furthermore, the assembly of the core is simplified and, as a result, an economical manufacturing process is made possible at lower costs.

Assembly is particularly economical if the outer casing (housing part) is so small that no fastening of the end of the wound tape is necessary. The cracking of the outer layer of the wound core is so small that it does not result in a significant change in its magnetic properties. The concept described here for producing a magnetic core is particularly suitable for strips made of comparatively brittle magnetic material (eg nanocrystalline strips heat-treated under tensile stress in a continuous furnace). Since the carrier on which the tape is wound also forms part of the core housing, there is no need to remove the wound core from a winding shaft, which can easily break the brittle band could lead. The concepts described here also make handling the wound core during the further production steps (including before closing the housing) safer and easier.

Depending on the application, the arrangement of the magnetic core in a closed housing can be an essential prerequisite for further processing, such as winding the core with a conductor (to produce a coil). Electrical insulation can also play a role here, since the metal magnetic core shortens the clearance and creepage distance between two windings arranged on the core. If, according to the exemplary embodiments described here, the magnetic core is wound directly onto a carrier, which then forms part of the housing of the core, as mentioned, the otherwise necessary assembly gaps are eliminated (i.e. there is no play between the toroidal band core and the carrier), which is why there is more magnet volume is possible with the same installation space as with conventional concepts. If insulation is not required in an application, the outer shell of the housing can be omitted and the carrier on which the magnetic core is wound forms an open housing.

$$0\le \mathrm{b}<2,$$

$$0\le \left(\mathrm{b}+\mathrm{c}\right)<2,$$

$$0\le \mathrm{d}<5,$$

$$10<\mathrm{x}<18,$$

$$5<\mathrm{y}<11$$

und $$0\le \mathrm{z}<2.$$

The soft magnetic band can be made of an iron alloy or a cobalt alloy. In some embodiments, the strip is made of an iron alloy described by the formula Fe _100-abcdxyz Cu _a Nb _b M _c T _d Si _x B _y Z _z . M denotes one or more elements from the group of elements molybdenum (Mo), tantalum (Ta) or zirconium (Zr), T denotes one or more elements from the group of elements vanadium (V), manganese (Mn), chromium ( Cr), cobalt (Co) or nickel (Ni) and Z one or more elements from the group of elements carbon (C), phosphorus (P) or germanium (Ge). The indices a, b, c, d, x, y, and z are given in atomic % and satisfy the following conditions: $$0\le \mathrm{a}<1.5,$$

$$0\le \mathrm{b}<2,$$

$$0\le \left(\mathrm{b}+\mathrm{c}\right)<2,$$

$$0\le \mathrm{d}<5,$$

$$10<\mathrm{x}<18,$$

$$5<\mathrm{y}<11$$

and $$0\le \mathrm{e.g}<2.$$

The alloy can contain up to 1 atomic percent of impurities.

$$\mathrm{0,1}<\mathrm{b}<\mathrm{1,5},$$

$$1\le \mathrm{c}<5,$$

$$0\le \mathrm{d}<5,$$

$$12<\mathrm{x}<18$$

$$5<\mathrm{y}<8,$$

$$0\le \mathrm{z}<2$$

In some embodiments, the ribbon is made of a cobalt alloy described by the formula Co _100-abcdxyz Fe _a Cu _b M _c T _d Si _x B _y Z _z . M denotes one or more elements from the group of elements niobium (Nb), molybdenum (Mo), and tantalum (Ta), T denotes one or more elements from the group of elements manganese (Mn), vanadium (V), chromium (Cr), and nickel (Ni) and Z one or more elements from the group of elements carbon (C), phosphorus (P) and germanium (Ge). The indices a, b, c, d, x, y, and z are given in atomic % and satisfy the following conditions: $$1.5<\mathrm{a}<15,$$

$$0.1<\mathrm{b}<1.5,$$

$$1\le \mathrm{c}<5,$$

$$0\le \mathrm{d}<5,$$

$$12<\mathrm{x}<18$$

$$5<\mathrm{y}<\mathrm{8th},$$

$$0\le \mathrm{e.g}<2$$

The alloy may contain up to 1 atomic percent, preferably up to 0.5 atomic percent, of impurities.

As mentioned, the tape can be heat treated, with the heat treatment being carried out under tension to achieve desired magnetic properties (Zina material). In some exemplary embodiments, the soft magnetic band has a nanocrystalline structure, in particular a nanocrystalline structure in which at least 50% by volume of the grains have an average size of less than 100 nm.

The soft magnetic tape can have a hysteresis loop with a central linear region, a remanence ratio, Jr /Js of remanence (Jr) to saturation induction (Js) of less than 0.1, and a ratio Hc/Ha of coercivity (Hc) to anisotropy field (Ha ) of less than 0.1. The permeability of the toroidal core can be in the range from 40 to 10,000.

In Fig. 1 illustrates an exemplary embodiment of a suitable carrier for producing a magnetic core with a housing. Diagram (a) of Fig. 1 shows the carrier 10, which essentially has the shape of a hollow prism (generally a cylinder with any base area), at the ends of which side walls 11 and 12 are arranged. The inner hole runs through the prism along its longitudinal axis. In the example shown is the prism is a cuboid with an approximately square base. However, differently shaped base areas are also possible. In the case of a circular shape, the carrier 10 has the shape of a circular cylinder. The side walls 11 and 12 and the middle part (the hollow prism) are an integral component and can, for example, be made of plastic (eg by injection molding).

Diagram (b) of Fig. 1 illustrates an outer shell 20 that matches the carrier 10 from diagram (a). In the present example, this also has a cuboid shape and its inner dimensions are chosen so that they exactly match the outer dimensions of the side walls 11 and 12 of the carrier 10, so that the outer shell 20 can be pushed over the carrier 20. When assembled, parts 10 (with side walls 11 and 12) and 20 form a closed housing.

Before the housing part 20 is pushed over the carrier 10, a soft magnetic tape is wound around the carrier 10 to produce a wound magnetic core 30. The length of the carrier 10 is dimensioned so that the soft magnetic band fits exactly between the two side walls 11 and 12. After the tape has been wound into the core, the outer cover 20 can be pushed over the wound carrier, whereby the wound core is enclosed on all sides by the housing. As mentioned above, the carrier 10 forms part of the housing. Diagram (c) of the Fig. 1 shows a cross section through the magnetic core 30 including the housing (parts 10, 20), the cutting plane being perpendicular to the longitudinal axis of the carrier 10. Diagram (d) of Fig. 1 shows a side view of the magnetic core arranged in the housing, with a conductor 40 being passed through the inner hole of the carrier 10.

Fig. 2 illustrates another example of a hollow prism or a hollow cylinder 10, however, consisting of two parts 10a 10b and with a division along the longitudinal axis. The side wall 11 and the part 10a are an integral component. The same applies to the side wall 12 and the part 10b. The parts 10a and 10b may be identical and symmetrical with respect to the longitudinal axis of the carrier 10. When assembled coaxially, parts 10a and 10b form a carrier that looks essentially the same as the carrier in Fig. 1 , diagram (a). The outer shell 20 off Fig. 2 is essentially the same as that in Fig. 1 , diagram (b). In one exemplary embodiment, a core is only wound around part 10a and part 10b completes the carrier 10 in the axial direction. In In this case, part 10b may be shorter along the longitudinal axis than part 10a. In another exemplary embodiment, a toroidal strip core is wound around both the part 10a and the part 10b. The wound parts 10a, 10b are then processed as in the left part of the Fig. 2 shown joined together and then connected to the part 20 to form a housing. In this case there are two toroidal cores in the housing. This concept can also be extended to three or more cores.

In the in Fig. 3 , Diagram (a), example shown, the carrier 10 has the shape of a hollow cylinder with an oval base. Unlike the previous examples, the side walls 11 (in Fig. 3 cannot be seen because it is covered) and 12 is not part of the carrier 10, but of the outer shell 20, which is divided into parts 20a and 20b along the longitudinal axis. The parts 20a and 20b can be the same, each have the shape of a half-shell, and together they form the outer shell 20. After the carrier 10 has been wrapped with the soft magnetic tape 30, the parts 20a and 20b can be placed over the core 30 arranged on the carrier 10 are pushed, the parts 20a and 20b together with the carrier 10 completely enclosing the wound core 30. The contour of the openings in the side surfaces 11 and 12 is substantially congruent with the outer contour of the carrier 10, so that the parts 20a and 20b can be pushed onto the end of the carrier 10 to complete the housing. Fig. 3 , Diagram (b), shows a cross section through the core 30 including the housing. Also in this example, the carrier 10 may be divided into two or more parts, and a separate core may be wrapped around each part. The supports are then joined together along the longitudinal axis, and after the housing has been completed, the cores are arranged next to one another (coaxially).

In the in Fig. 4 In the example shown, the carrier 10 has the shape of a hollow cylinder with a circular base, with a side wall 11 being connected to the hollow cylinder. The opposite side wall 12 is connected to the outer shell 20 (see Fig. 4 , diagram (b)). Fig. 4 , Diagram (c), shows the assembly of the housing using a longitudinal section view. In the example shown, the outer shell 20 (with side wall 12) is pushed from right to left over the core 30 wrapped around the carrier 10. The right end of the carrier 10 is pushed into the corresponding opening in the side wall 12, the end of the carrier 10 and the contour of the opening in the side wall 12 being shaped so that the carrier 10 is in the opening in the side wall 12 can snap into place. This means that the two parts are attached to each other using a snap-in connection. The same applies with regard to the outer contour of the side wall 11 and the corresponding end of the outer shell 20, which are also designed in such a way that the side wall 11 snaps into place at the end of the outer shell. In this way, the outer shell and the carrier can be held together in a form-fitting manner using the side walls 11 and 12. At the same time, the housing is closed around the core 30. In other examples, the housing parts can also be glued or welded (eg using ultrasonic welding).

The example from Fig. 5 can be used as a modification of the example Fig. 3 to be viewed as. In the example shown, the outer shell 20 is formed from two parts 20a, 20b, with the side wall 11 being connected to the part 20a and the side wall 12 being connected to the part 20b. The side wall and outer shell can each form an integral component. The side walls 11 and 12 each have an opening that can be pushed over one end of the cylindrical support 10.

Different than in the example Fig. 3 , the carrier 10 shows Fig. 5 in the middle there is a circumferential web 15, the outer contour of which can be designed such that the inner contour of the outer casing parts 20a, 20b can snap into the web 15 (snap-in connection). In this case, two coaxially arranged cores 30a, 30b can be wound on the carrier 10, a core to the left of the web 15 and another core to the right of the web 15. The two cores 30a and 30b can be made of the same material or of different materials with different magnetic properties exist. The contour of the cross-sectional area of the carrier 10 is in Fig. 5 not visible. It is understood that the cross-sectional area of the carrier 10 may have any shape, such as a circular shape as in the example Fig. 4 , or a square shape, like in the example Fig. 1 .

Fig. 6 illustrates an example of an inductive component with a magnetic core 30 including housing according to Fig. 4 and a coil wound around the core 30, for example a choke. The coil can be made of insulated copper wire. In another example, two or more coils can be wound around the core, for example to make a transformer or a power converter.

Fig. 7 is a cross-sectional representation (section plane normal to the longitudinal axis A), for example a cross-section through the in Fig. 4 shown core. The tape wound into the magnetic core is only shown schematically. The innermost layer (turn) is labeled 3.1, the penultimate layer (turn) is labeled 3.N-1 and the outermost, last layer is labeled 3.N. The core band layers are in Fig. 7 not completely shown. It is desirable that the distance d (the clearance) between the outermost layer 3.N and the inside of the outer shell 20 is as small as possible. If the outermost layer 3.N of the tape is not attached to the underlying layer 3.N-1 (e.g. using an adhesive tape or spot welding), the last layer will protrude in an angular range α (due to the spring effect of the tape). , whereby the smaller the distance d, the smaller the angular range α.

In Fig. 7 A cross-section shows the design of a core in which the outer strip layers have not been fixed, meaning that the spiral winding of the core opens slightly. The distance d between the outermost band layer of the core and the inner wall of the housing must be chosen to be as small as possible so that the area in which there is an air gap between the band layers of the core (angle α) does not become too large. In practice, it is possible to make the play d so small that the last band layer 3.N does not have to be attached and the protrusion of the band end in the angular range α does not significantly influence the magnetic properties of the core. This means that the effective permeability and thus the inductance of the toroidal band core does not change significantly due to the band end protruding in the angular range α□□. In particular, the inductance of the toroidal band core is reduced by no more than 10% due to the band end protruding in the angular range α. It is understood that inductance usually characterizes a coil wound around the core, where the inductance depends on the number of turns of the coil. However, you can also define an inductance for a magnetic core if the number of turns N is set to a standard value such as N=1.

Fig. 8 shows a side view of a circular cylindrical carrier 10 (with side wall 12). The carrier 10 can be designed essentially like the carrier Fig. 1 , Diagram (a), with the difference that the central part of the beam 10 (without the side walls 11, 12) has a circular cross section (instead of a square one cross section). For winding with a soft magnetic tape 30 to produce a core, the carrier 10 is placed on a shaft 1. In order to ensure an easily detachable, positive connection between the shaft 1 and the carrier 10, the shaft 1 can have a projection 2 which is inserted into a corresponding groove in the inner hole of the carrier when the carrier 10 is plugged onto the shaft 1. Other positive connections (e.g. a feather key) are also possible.

Some of the exemplary embodiments described here are summarized below. This is not an exhaustive list of technical features, but merely an exemplary summary.

One exemplary embodiment relates to a method for producing a toroidal strip core. The process involves attaching a carrier to a shaft (cf. Fig. 8 ), wherein the carrier has a through opening along a longitudinal axis into which the shaft can be inserted. The method further comprises winding (at least) a soft magnetic tape around the carrier to form (at least) a toroidal tape core by rotating the shaft. After the winding process, the carrier is removed from the shaft. In some embodiments, the method further comprises enclosing the toroidal core in a housing by at least one housing part (see e.g Fig. 1, 2 and 4 , outer shell 20, as well Fig. 3 and 5 , housing parts 20a, 20b) are pushed over the toroidal band core and connected to the carrier, the carrier itself forming part of the housing.

In the examples described here, that part of the carrier around which the soft magnetic tape is wound has the shape of a hollow cylinder. The hollow cylinder can be circular (cf. Fig. 4 ), oval (cf. Fig. 3 ) or rectangular (cf. Fig. 1 ) have a cross section. Cylinders with a rectangular or square cross section are also called prisms. The carrier can consist of an insulator (e.g. a plastic) or a non-magnetic metal.

The carrier on which the toroidal band core is located and/or the at least one housing part (e.g. the outer shell 20, cf. Fig 4 ), which is pushed over the annular band core, has at least one side wall, which lies essentially at right angles to a longitudinal axis of the carrier. The side walls allow for a closed housing for the toroidal core. In the in Fig, 1 In the example shown, both side walls are arranged on the carrier, in which in Fig. 4 In the example shown, one side wall is part of the carrier and the other side wall is part of the outer shell. In the in Fig. 3 In the example shown, both side walls are parts of the (two-part) outer shell. The individual housing parts (support and outer shell) can be mounted together in a form-fitting manner, for example using snap-in connections (latching connections), to form a closed housing. As an alternative to a positive connection, gluing or ultrasonic welding can be used to connect the housing parts.

In one embodiment, the beginning of the soft magnetic tape is fixed on the carrier before winding, for example using adhesive or adhesive tape. It is not absolutely necessary to fix the end of the band to the underlying band layer. The end of the band, which can protrude due to the spring effect of the band, is held by the inside of the housing and secures the ring band core from unwinding. The clearance between the housing and the ring band must be dimensioned accordingly small.

A further exemplary embodiment relates to a device with a carrier which has a continuous opening along a longitudinal axis, and at least one soft magnetic tape wound around the carrier to form an annular tape core. The soft magnetic tape is wound directly onto the carrier so that there is no play between the toroidal tape core and the carrier. The device can have at least one housing part which surrounds the toroidal band core and is connected to the carrier in such a way that the at least one housing part together with the carrier forms a closed housing around the toroidal band core. In one embodiment, the soft magnetic strip was heat treated before winding, with the desired magnetic properties being set during the heat treatment by applying a tensile stress.

The technical features of the individual exemplary embodiments described here can be combined to form further exemplary embodiments - provided they are not mutually exclusive alternatives.

Claims (15)

Procedure which includes the following: Inserting a carrier (10), which has a continuous opening along a longitudinal axis (A), or a part of the carrier (10), onto a shaft (1); Winding at least one soft magnetic band around the carrier (10) to form at least one toroidal band core (30) by rotating the shaft (1); and Remove the carrier (10) including the toroidal core (30) from the shaft (1). The method of claim 1, further comprising:
Enclosing the toroidal band core (30) in a housing by pushing at least one housing part (20, 20a, 20b) over the toroidal band core (30) and connecting it to the carrier (10), the carrier (10) itself forming a further housing part. The method according to claim 1 or 2,
wherein that part of the carrier (10) around which the soft magnetic band is wound has the shape of a hollow cylinder, for example with a circular, oval or rectangular cross section. The method according to one of claims 1 to 3, wherein an outer end of the wound band is not attached to an underlying layer of the band, but is held by an inside of the at least one housing part (20, 20a, 20b), so that the ring band core (30) is secured against unwinding of the soft magnetic band, and wherein in particular a play between the toroidal band core (30) and the inside of the at least one housing part (20, 20a, 20b) is so small that the effective permeability and thus the inductivity of the toroidal band core (30) is due to the protrusion of the end of the wound band reduced by no more than 10%. The method according to one of claims 1 to 4, wherein the carrier (10) consists of a non-magnetic, electrically non-conductive material, in particular a plastic, or wherein the carrier (10) consists of a non-magnetic metal, for example aluminum, magnesium or zinc. The method according to one of claims 2 to 5, as far as related to claim 2, wherein the carrier (10) and/or the at least one housing part (20, 20a, 20b), which is pushed over the toroidal band core (30), has at least one side wall (11, 12) which is substantially perpendicular to a longitudinal axis of the carrier (10) lies, wherein in particular the at least one housing part (20, 20a, 20b) and the carrier (10) are mounted to one another by means of snap-in connections or by means of gluing or by means of ultrasonic welding. The method according to one of claims 1 to 6,
before winding, the beginning of the soft magnetic tape is fixed on the carrier, for example using adhesive or adhesive tape. The method according to one of claims 1 to 7,
wherein the continuous opening of the carrier (10) and the shaft (1) are designed such that the carrier (10) is held in a form-fitting manner on the shaft (1). The method according to one of claims 1 to 8, wherein the soft magnetic band is made of an alloy

Fe _100-abcdxyz Cu _a Nb _b M _c T _d Si _x B _y Z _z

consists and where M one or more of the elements Mo, Ta or Zr, T one or more of the elements V, Mn, Cr, Co or Ni and Z is one or more of the elements C, P or Ge, and where a, b, c, d, x, y, z are given in atomic %, and a, b, c, d, x, y, z satisfy the following conditions: $$0\le \mathrm{a}<1.5,$$

$$0\le \mathrm{b}<2,$$

$$0\le \left(\mathrm{b}+\mathrm{c}\right)<2,$$

$$0\le \mathrm{d}<5,$$

$$10<\mathrm{x}<18,$$

$$5<\mathrm{y}<11$$

and $$0\le \mathrm{e.g}<2,$$

and the alloy has up to 1 atomic percent impurities, or wherein the soft magnetic band is made of an alloy

Co _100-abcdxyz Fe _a Cu _b M _c T _d Si _x B _y Z _z

consists and where M one or more of the elements Nb, Mo, and Ta, T one or more of the elements Mn, V, Cr and Ni, and Z is one or more of the elements C, P or Ge, and where a, b, c, d, x, y, z are given in atomic %, and a, b, c, d, x, y, z satisfy the following conditions: $$1.5<\mathrm{a}<15,$$

$$0.1<\mathrm{b}<1.5,$$

$$1\le \mathrm{c}<5,$$

$$0\le \mathrm{d}<5,$$

$$12<\mathrm{x}<18$$

$$5<\mathrm{y}<\mathrm{8th},$$

$$0\le \mathrm{e.g}<2$$

and the alloy has up to 1 atomic percent, preferably up to 0.5 atomic percent, of impurities. The method according to one of claims 1 to 9, wherein the soft magnetic band has a nanocrystalline structure in which at least 50% by volume of the grains have an average size of less than 100 nm, wherein the soft magnetic band in particular has a hysteresis loop with a central linear part, a remanence ratio, Jr /Js , <0.1, and a ratio H _c /H _a of coercive field strength, H _c , to anisotropy field strength, H _a , of less than 0, 1 has, The method according to one of claims 1 to 10,
wherein the soft magnetic tape was heat treated under tensile stress. Procedure which includes the following: Plugging a first part of a carrier (10a), which has a continuous opening along a longitudinal axis (A), onto a shaft (1); winding a first soft magnetic tape around the first part of the carrier (10) to form a first toroidal tape core (30) by rotating the shaft (1); Removing the first part of the carrier (10) together with the first toroidal band core (30) from the shaft (1); Attaching a second part of a carrier (10b); winding a second soft magnetic tape around the second part of the carrier (10b) to form a second toroidal tape core by rotating the shaft (1); Removing the second part of the carrier (10b) together with the second toroidal band core from the shaft (1); and Assembling the first and second parts of the carrier (10a, 10b) together with the toroidal strip cores wound thereon, the first and second parts of the carrier (10a, 10b) lying coaxially to one another. The method of claim 12, further comprising:
Enclosing the toroidal cores in a housing by pushing at least one housing part (20, 20a, 20b) over the toroidal cores and connecting it to the two parts (10a, 10b) of the carrier (10), the carrier (10) itself being a further housing part forms. A device comprising: a carrier (10) which has a continuous opening along a longitudinal axis (A), at least one soft magnetic band wound around the carrier (10) to form a ring band core (30), wherein the band is wound directly onto the carrier (10) so that there is no play between the toroidal band core (30) and the carrier. The device according to claim 14, further comprising: at least one housing part (20, 20a, 20b) surrounding the toroidal core (30) and connected to the carrier (10) such that the at least one housing part (20, 20a, 20b ) together with the carrier (10) forms a closed housing around the toroidal band core.

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