Electrical Arrangement with a Transformer for Transmitting Signals from a Primary Side to a Secondary Side

Abstract

Provided is an electrical arrangement with a printed circuit board built up in parallel layers, comprising a shield, a transformer for transmitting signals from a primary side to a secondary side, the transformer having a first coil winding and a second coil winding and a third coil winding, the first coil winding forming the primary side of the transformer and the second and third coil windings forming the secondary side of the transformer, and a magnetic conductor, wherein the circuit board has openings which are penetrated by parts of the magnetic conductor, and the magnetic conductor and the shield and the transformer are magnetically coupled, and wherein the shield is a potential-free shield.

Claims

1. An electrical arrangement with a printed circuit board built up in parallel layers, comprising: a shield; a transformer for transmitting signals from a primary side to a secondary side with a first coil winding, a second coil winding, and a third coil winding, the first coil winding forming the primary side of the transformer and the second and third coil windings forming the secondary side of the transformer; and a magnetic conductor, wherein the circuit board has openings which are penetrated by parts of the magnetic conductor, wherein the magnetic conductor and the shield and the transformer are magnetically coupled, and wherein the shield is a potential-free shield.

2. The arrangement of claim 1, wherein the shield is a shield winding.

3. The arrangement of claim 1, wherein the printed circuit board has at least one first layer and the second and third coil windings are arranged side-by-side within the first layer.

4. The arrangement of claim 3, wherein the circuit board has at least one second layer and the first coil winding is arranged in the second layer.

5. The arrangement of claim 4, wherein the first and second layers are immediately adjacent to each other.

6. The arrangement of claim 4, wherein the shield is arranged in a third layer of the circuit board which is immediately adjacent to the second or first layer.

7. The arrangement of claim 4, wherein a first part of the shield is arranged in a third layer of the circuit board and a second part of the shield is arranged in a fourth layer of the circuit board, wherein the third layer is immediately adjacent to the second or first layer.

8. The arrangement of claim 1, wherein the circuit board has an uppermost layer which can be equipped with components and/or a lowermost layer which can be equipped with components, and wherein the components interact with the transformer electrically and/or magnetically.

9. The arrangement of claim 8, wherein the components at least partially overlap with the transformer in a projection perpendicular to the parallel layers.

10. The arrangement of claim 1, wherein the first and/or second and/or third coil winding encloses one or more of the openings.

11. The arrangement of claim 10, wherein centers of three openings in the circuit board lie on a connecting line.

12. The arrangement of claim 10, wherein the magnetic conductor comprises two parts extending parallel to the connecting line.

13. The arrangement of claim 12, wherein the centers of the three openings in the circuit board form an isosceles or equilateral triangle.

14. The arrangement of claim 1, wherein the shield is a completely closed metallic ring.

15. The arrangement of claim 1, wherein the shield is an open metallic ring with a slot-shaped opening.

16. The arrangement of claim 1, wherein, in a projection perpendicular to the parallel layers, the extent of the shield in the third layer is less than or equal to the extent of the primary side of the transformer in the second layer and/or the secondary side of the transformer in the first layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention will be explained in more detail in the following detailed description based on exemplary embodiments, wherein reference is made to the drawings in which:

[0037] FIG. 1 shows a first sectional view of an electrical arrangement according to a first exemplary embodiment;

[0038] FIG. 2 shows a second sectional view of the electrical arrangement according to the first exemplary embodiment;

[0039] FIG. 3 shows a third sectional view of the electrical arrangement according to the first exemplary embodiment;

[0040] FIG. 4 shows a first sectional view of an electrical arrangement according to a second exemplary embodiment;

[0041] FIG. 5 shows a second sectional view of the electrical arrangement according to the second exemplary embodiment;

[0042] FIG. 6 shows a third sectional view of the electrical arrangement according to the second exemplary embodiment;

[0043] FIG. 7 shows a first sectional view of an electrical arrangement according to a third exemplary embodiment;

[0044] FIG. 8 shows a second sectional view of the electrical arrangement according to the third exemplary embodiment;

[0045] FIG. 9 shows a third sectional view of the electrical arrangement according to the third exemplary embodiment;

[0046] FIG. 10 shows a top view of the electrical arrangements according to a further exemplary embodiment.

[0047] In the drawings, the same or functionally similar elements are indicated by the same reference numerals.

MODES FOR CARRYING OUT THE INVENTION

[0048] FIG. 1 shows a sectional view of an electrical arrangement according to an embodiment. Electrical arrangement 100 comprises printed circuit board 10 (only partially shown) which consists of layers 12 and 14 that are parallel to each another. Between layer 12 and layer 14, there is a transformer. The transformer comprises coil winding 20, which form the primary side of the transformer, and coil windings 30 and 40, which form the secondary side of the transformer. As shown, coil windings 30 and 40 (in layer 16) can be arranged side-by-side. Furthermore, as shown in FIG. 1, the primary side and the secondary side may be arranged in immediately adjacent layers 16 and 18.

[0049] Electrical arrangement 100 further comprises magnetic conductor 50 which, in the sectional view of FIG. 1, has the shape of a horizontal figure of eight, wherein magnetic conductor 50 has vertically extending sections (hereinafter referred to as legs) 52, 54 and 56 which penetrate circuit board 10. Coil winding 30 winds (only) around outer leg 52, coil winding 40 winds (only) around outer leg 56 and coil winding 20 winds (only) around inner leg 54. Electrical arrangement 100 further comprises shield 60 which is also arranged between layer 12 and layer 14 and winds around both outer legs. In further embodiments, shield 60 may also be arranged above layer 12 or below layer 14 and, in particular, extend around magnetic conductor 50. Shield 60 may be formed as a shield winding or as a homogeneous layer. For example, shield 60 may be formed by conductive tracks on a substrate (for example, a non-conductive foil) or by a continuously conductive layer (for example a conductive foil such as a copper foil).

[0050] As shown in FIG. 2 and FIG. 3, magnetic conductor 50 may consist of two (structurally identical) parts, the yokes 58 of which extend parallel to a line V which connects two or three centers of the openings. In particular, the connecting line V in the sectional views shown in FIG. 2 and FIG. 3 may lie in a plane to which the parts of the magnetic conductor are mirror symmetrical. As shown, shield 60 may be formed as a completely closed ring. In addition, as indicated by the dashed lines marked with the letter S, shield 60 may be formed as an open ring with a slot-shaped opening.

[0051] As shown, coil windings 20, 30, and 40 may extend farther than shield 60 such that the coil windings are not completely covered by shield 60 in a projection perpendicular to the parallel layers. In other embodiments, coil windings 20, 30 and 40 may have the same extent or a smaller extent than shield 60. Coil winding 20, coil winding 30, and coil winding 40 may furthermore have (substantially) the same thickness. Furthermore, shield 60 may have a thickness which is (essentially) the same as the thickness of coil winding 20, coil winding 30, and coil winding 40.

[0052] FIG. 4, FIG. 5, and FIG. 6 show a modification of the electrical arrangement shown in FIG. 1, FIG. 2, and FIG. 3, which differs from electrical arrangement 100 shown in FIG. 1, FIG. 2, and FIG. 3 in that coil winding 30 and coil winding 40 of the secondary side are arranged between coil winding 20 of the primary side and shield 60, whereas in FIG. 1, FIG. 2, and FIG. 3, coil winding 20 of the primary side is arranged between shield 60 and coil windings 30 and 40 of the secondary side. In further possible embodiments, the order of the layers may also be the other way around, so that, deviating from FIG. 4, shield 60 is arranged on top (i.e., on the upper side of the transformer) and coil winding 20 is arranged at the bottom (i.e., at the lower side of the transformer).

[0053] FIG. 7, FIG. 8, and FIG. 9 show a modification of the electrical arrangements shown so far, which differs from the electrical arrangements shown so far in that coil winding 20 of the primary side and coil winding 30 and coil winding 40 of the secondary side are arranged between two shields 60. The shields may be structurally identical or have (essentially) the same dimensions and, as shown, be arranged such that they are mapped onto one another in a projection perpendicular to parallel layers 12 and 14. In further possible embodiments, one shield may be larger than the other shield, or one of the shields may be divided into two (partial) shields (for example an inner and an outer shield).

[0054] FIG. 10 shows a top view of printed circuit board 10, which is equipped with electrical components 200, 300, 400, and 500. Component 200 is electrically connected to the primary side and components 300 and 400 are electrically connected to the secondary side. Component 500 is arranged above the transformer so that it overlaps with the transformer in a projection perpendicular to the parallel layers. In further possible embodiments, one or more of the components 200, 300, 400 may be arranged above the transformer and interact electrically and/or magnetically with the transformer.

LIST OF REFERENCE SIGNS

[0055] 10 circuit board [0056] 12 circuit board layer [0057] 14 circuit board layer [0058] 16 circuit board layer [0059] 18 circuit board layer [0060] 20 coil winding [0061] 30 coil winding [0062] 40 coil winding [0063] 50 magnetic conductor [0064] 52 leg [0065] 54 leg [0066] 56 leg [0067] 58 yoke [0068] 60 shield [0069] 100 arrangement [0070] 200 component [0071] 300 component [0072] 400 component [0073] 500 component [0074] V connecting line [0075] S slot