EP1812938B1 - Inductive circuit element and method for assembly of an inductive circuit element - Google Patents

Abstract

For inductive circuit elements, the production of windings from U-shaped curved wire elements is known, which arch over a core and, together with conductor tracks soldered into the ends thereof, form complete windings. The above can lead to thermal problems and large dispersion of the electromagnetic parameters. According to the invention, an inductive circuit element is thus provided, whereby U-shaped first hoops (2) and second hoops (4) are arranged in opposition and directly connected to each other such as to enclose the annular core (3) as complete windings. The group of the first hoops (2) is thus fixed to a support circuit board (1) and the group of the second hoops (4) are fixed on an opposing circuit board (5).

Description

The invention relates to an inductive circuit element with a toroidal core and a composite of U-shaped bracket winding material.

Furthermore, the invention relates to a method for mounting a circuit element with a toroidal core and a composite of U-shaped bracket winding.

According to the state of the art, it is known for inductive circuit elements such as transformers or chokes to realize the current-carrying windings by using bow-shaped (U-shaped) wire elements, which arch over the core cross-section and are inserted into the printed circuit board individually and parallel to each other, so that they form complete turns together with corresponding traces to which they are soldered.

That's how it shows DE3720739 (Meinel ) a substantially O-shaped core, which is held by soldered Windungsbügel, which serve to form two, distributed on both legs windings on the board.

While this technique eliminates a conventional winding operation, the required traces on the board are limited in cross-section so that thermal problems occur at high currents. The heat generated in the tracks can then no longer be dissipated via the board without additional cooling measures. The tracks must therefore be strengthened, which in turn is associated with overtime. In addition, the known construction has the disadvantage that individual circuit elements of identical construction have large variations in the electrical-magnetic parameters.

Another type of arrangement U-shaped wire hanger is known from the JP 05090035 A , which will be the closest prior art. Here, the wire bow made of lead wire are formed and arranged around a toroidal core, wherein the ends of the upper bracket are inserted into quiver-shaped forms of the lower bracket and soldered. A mechanical assembly is difficult because the upper and lower bracket must be mounted alternately around the toroidal core.

In the US 4 878 291 A a method for mounting an inductive circuit element is specified, wherein the winding material composed of U-shaped and S-shaped bracket. The distance between adjacent brackets can easily change in this arrangement due to external influences during assembly or during operation, which has a negative effect on the constancy of the electro-magnetic parameters.

An Indian US Pat. No. 3,638,156 specified method describes the composition of a wound on a ceramic base material. In this case, a U-shaped base body is provided with U-shaped conductor tracks, in which a cylindrical core is inserted, wherein the adjacent ends of the conductor tracks are connected diagonally with sheet-metal brackets. Such a ceramic base body is difficult to manufacture for an annular core, which is why the solution for toroidal cores is not considered.

The invention is therefore based on the object to provide an inductive switching element with a toroidal core and a composite of U-shaped bracket winding material, which is easy to manufacture and has constant electrical-magnetic parameters. Furthermore, a method for easy installation should be specified.

According to the invention this object is achieved with an inductive circuit element of the type mentioned in at the first bracket and second bracket are provided and the first bracket so arranged the second bracket opposite and are directly connected to each other that they enclose the toroidal core as comprehensive turns and wherein the brackets are formed from sheet metal and have at their back a web, with all the first bracket on a first carrier board and all second bracket are mounted on a second carrier board.

The circuit element according to the invention has the advantage that the turns are constructed solely of brackets, which can be adapted in their dimension to the thermal loads. Furthermore, it is achieved by a stable mounting on the carrier boards with constant distances between the individual windings that the electrical-magnetic parameters of identical circuit elements compared to conventional designs have lower scattering.

A particularly favorable Felddurchdringverhalten is achieved with the fact that the bracket made of silvered beryllium, copper or bronze. This results in a uniform distribution of the current and the thermal load.

Another advantage lies in the simple realization of windings of desired number of turns by at least one pair of side by side arranged first bracket is not connected to a second bracket together and so at least one ring core comprising winding with terminals at the attachment points of the coil ends forming bracket is given. Thus, the circuit elements can be integrated directly into the board by the contact is given by traces that lead directly to the solder joints for attachment of the winding ends forming bracket.

In an advantageous embodiment, it is provided that the bracket on the leg ends have contact surfaces at which they are soldered together or that the bracket at one leg end a male connector and at the other leg end male plug and the strap are connected plugged. This results in a simple assembly of the Wicklungsguts.

To further reduce costs, it is advantageous if the first bracket and the second bracket are made identical. As a result, all the stirrups can use the same tools and production steps for the production.

Furthermore, it is advantageous if the carrier boards are made of a ceramic material, so that the resulting heat can be better dissipated. Another advantage is the low deformation when heating the carrier boards.

The assembly of the circuit element according to the invention can be carried out particularly easily by rotationally symmetrically attached to a first carrier board U-shaped bracket and in the resulting first half of the winding material, a toroidal core is inserted electrically insulated, spans with U-shaped second bracket in the manner is that each adjacent first bracket are connected by second bracket and so complete turns arise.

Assembly is particularly favorable when the second bracket spanning the toroidal core is preassembled on a common second carrier board. This can be done as in the attachment of the first bracket on the first carrier board by soldering or gluing and leads to a uniform distance between the brackets.

It is important to ensure that those second bracket are omitted, which cause by their absence interrupting the otherwise self-contained winding and so the form opposite ends of the first bracket winding ends of at least one non-self-contained winding. If only a second or more juxtaposed second bracket omitted, then there is a winding. If several non-adjacent second bracket omitted, then there are correspondingly more windings.

Depending on the selected version of the bracket, the placement of the group of second bracket on the group of the first bracket can then be done by soldering or plugging.

Fig. 1:

eine schematische Darstellung eines erfindungsgemäßen Schaltungselementes mit gesteckt verbundenen Bügel und einer Wicklung

Fig. 2:

eine schematische Darstellung eines erfindungsgemäßen Schaltungselementes mit gelötet verbundenen Bügel und zwei Wicklungen

Fig. 3:

Aufriss eines Bügels für gesteckte Verbindung

Fig. 4:

Seitenriss eines Bügels für gesteckte Verbindung

Fig. 5:

Grundriss eines Bügels für gesteckte Verbindung

Fig. 6:

Ansicht A eines Bügels für gesteckte Verbindung wie in Fig. 5 angegebenen

The invention will be explained in more detail with reference to figures. They show by way of example:

Fig. 1:

a schematic representation of a circuit element according to the invention with plugged connected bracket and a winding

Fig. 2:

a schematic representation of a circuit element according to the invention with soldered connected bracket and two windings

3:

Outline of a bracket for mating connection

4:

Side view of a bracket for plugged connection

Fig. 5:

Floor plan of a stirrup for mating connection

Fig. 6:

View A of a strap for mated connection as in Fig. 5 specified

Fig. 1 shows an inventive switching element with bracket, which are plugged together, with a variant is selected with a winding surrounding the entire ring core.

The base used is a carrier board 1 made of ceramic. These are the first bracket 2 with the off Fig. 3 apparent web 10 rotationally symmetrical soldered to the axis of symmetry of the toroidal core 3, wherein the individual solder joints with each other have no electrically conductive connection allowed to. The distance between the individual first bracket 2 is constant.

In this group first bracket 2 of the toroidal core 3 is inserted electrically isolated. This is accomplished by isolating the toroidal core 3 prior to insertion with a dielectric material. The toroidal core 3 spanning second bracket 4 connect two juxtaposed first bracket 2 in such a way that complete windings are given.

The winding formed from the bracket is interrupted at one point by the absence of a second bracket. As a result, the first bracket 6 and 7 to winding ends, which can be contacted via printed conductors 8 and 9 on the carrier board 1 with a circuit.

The group of the second bracket 4 is also soldered to a common carrier board 5, wherein also here there is no electrically conductive connection between the solder joints. About the support boards 1 and 5 due to the thermally well conductive connection with the brackets 2 and 4, the resulting heat during operation dissipated.

Fig. 2 also shows a circuit element according to the invention, in which case the variant of brackets 2 and 4 soldered together is shown. Due to the absence of two second bracket 4, the toroidal core 3 is enclosed by two windings whose winding ends form the first brackets 6 and 7. These can be contacted via the tracks 8 and 9 on the carrier board 1 with a circuit.

The in the Fig. 3 to 6 illustrated bracket is the plug-in version made of sheet metal. Fig. 3 shows the U-shape of the bracket, which has a beveled web 10 on the back. The first leg end 11 is designed as a plug female, wherein the leg is slotted in the middle and the resulting two leg segments as off Fig. 6 are clearly spread apart, so that they serve as a clamping receptacle for the second leg end 12. This second leg end 12 is designed as a straight sheet segment with rounded edges.

Fig. 5 shows the slight S-shape of the temple. The extent of the bend is dependent on the pitch of the winding and causes the mating plug female and male plug of the brackets to be connected to each other 2 and 4 lie in a common plane.

Claims (10)

1. Inductive circuit element having a toroidal core (3) and a winding material composed of u-shaped bails (2, 4), with first bails (2) and second bails (4) being provided and with the first bails (2) being arranged opposite the second bails (4) and being directly connected to one another such that they surround the toroidal core (3) as encompassing turns, characterised in that the bails (2, 4) are made of sheet metal and have a rib (10) on their rear, with which rib all first bails (2) are fastened to a first printed circuit board (1) and all second bails (4) are fastened to a second printed circuit board (5).
2. Inductive circuit element according to claim 1, characterised in that the bails (2, 4) consist of silver-plated beryllium, copper or bronze.
3. Inductive circuit element according to claim 1 or 2, characterised in that a pair of first bails (2) is not connected by second bails (4) and the bails (6, 7) forming winding ends in this way are connected to terminal contacts.
4. Inductive circuit element according to claims 1 to 3, characterised in that the first bails (2) and the second bails (4) have contact surfaces on the leg ends, at which they are soldered together or, that the first bails (2) and the second bails (4) comprise a female connector at one leg end and a male connector at the other leg end and the first bails (2) are linked by plugging them into to the second bails (4).
5. Inductive circuit element according to claims 1 to 4, characterised in that first bails (2) and second bails (4) are constructed in the same way.
6. Inductive circuit element according to one of the preceding claims, characterised in that the printed circuit boards (1, 5) are composed of a ceramic material.
7. Method for assembling a circuit element according to one of claims 1 to 6, characterised in that u-shaped first bails (2) are fastened in a rotationally-symmetrical fashion on a first printed circuit board (1) and a toroidal core (3) is placed in the first half of the winding material thus formed in an electrically-insulated fashion, said toroidal core being spanned above by the U-shaped second bails (4) such that first bails (2) lying in each instance next to one another are connected by means of second bails (4), thereby producing complete windings.
8. Method for assembling a circuit element according to claim 7, characterised in that the second bails (4) spanning over the toroidal core (3) are preinstalled on a shared second printed circuit board (5).
9. Method for assembling a circuit element according to claim 7 or 8,characterised in that the bails (2, 4) are soldered or glued to the printed circuit boards (1, 5).
10. Method for assembling a circuit element according to one of claims 7 to 9, characterised in that the group of second bails (4) are soldered to the group of first bails (2) or that the group of second bails (4) are plugged onto the group of first bails (2).

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