Wake-up coil for waking up an electrical device, having reduced space requirements

Abstract

The present invention relates to a wake-up coil for waking up an electrical device, comprising a first coil unit having a first winding which extends in a first circuit board plane and a second coil unit having a second winding which extends in a second circuit board plane parallel to the first circuit board plane, wherein: the first coil unit has a first contacting region and a first coil region; the second coil unit has a second contacting region and a second coil region; the first winding has, in the first contacting region, a first inner contact inside the first winding and a first outer contact outside the first winding, for electrically contacting the first winding; the second winding has, in the second contacting region, a second inner contact inside the second winding and a second outer contact outside the second winding, for electrically contacting the second winding; the first coil region and the second coil region are arranged such that they overlap perpendicularly to the first circuit board plane; the first contacting region is arranged outside the first coil region; the second contacting region is arranged outside the second coil region; and the first coil unit is designed to induce a voltage in the second coil unit by means of an electric current through the first winding, in order to wake up an electrical device.

Description

[0001] R.414789

[0002] - 1 -

[0003] Description

[0004] title

[0005] Wake-up coil for waking up an electrical device with reduced space requirements

[0006] State of the art

[0007] The present invention relates to a wake-up coil for waking up an electrical device and the associated electrical device.

[0008] Wake-up coils typically consist of two electrical circuits. A current through the first circuit induces a voltage in the second circuit to wake up an electrical device connected to the second circuit. Coils are used to transmit the necessary electrical energy. The space required for existing wake-up coils is primarily determined by the necessary clearances and creepage distances, rather than by the technically required effective coil area.

[0009] The electrical contacts of the various circuits are arranged both inside and outside the coil's geometry. The large space requirement is due to the necessary distances between the two electrical contacts inside the coil, the necessary distances between the inner contacts and the coil, and the required clearance between the coil and other components to prevent voltage flashovers or leakage currents. Ideally, a wake-up coil would be desirable that, while requiring less surface area on the circuit board, could efficiently transfer electrical energy to wake up an electrical device.

[0010] Disclosure of the invention

[0011] The awakening coil according to the invention with the features of claim 1 and the electrical device with the features of claim 12 has the advantage R.414789

[0012] - 2 - that the required circuit board area for the wake-up coil can be reduced, thus saving costs and installation space. Furthermore, the wake-up coil according to the invention enables efficient transmission of electrical energy. This is achieved according to the invention by the fact that the wake-up coil comprises a first coil unit and a second coil unit. The first coil unit has a first winding that extends in a first circuit board plane, and the second coil unit has a second winding that extends in a second circuit board plane that is arranged parallel to the first circuit board plane.Furthermore, the first coil unit comprises a first contact area and a first coil area, wherein the first winding in the first contact area has a first inner contact within the first winding and a first outer contact outside the first winding to electrically contact the first winding. Furthermore, the second coil unit comprises a second contact area and a second coil area, wherein the second winding in the second contact area has a second inner contact within the second winding and a second outer contact outside the second winding to electrically contact the second winding. The first coil area and the second coil area are arranged perpendicular to the first printed circuit board plane and overlap each other.The first contact area is located outside the first coil area, and the second contact area is located outside the second coil area. The first coil unit is configured to induce a voltage in the second coil unit by passing an electric current through the first winding, thus waking up an electrical device. By dividing the winding into a coil area and a contact area, the first contact area of ​​the first coil unit can be spatially separated from the second contact area of ​​the second coil unit. This allows the necessary air and creepage distances between the two circuits to be easily ensured without affecting the arrangement of the coil areas. Consequently, a space saving of up to 50% can be achieved compared to prior art wake-up coils where the contact area is located within the coil area.The first winding and / or the second winding preferably comprise five to ten turns of an electrical conductor. The windings are preferably produced by etching or coating a printed circuit board layer. R.414789.

[0013] - 3 -

[0014] For example, the wake-up coil can be implemented on an FF4 circuit board.

[0015] The printed circuit board layers are preferably electrically isolated from each other. In particular, the distance between the printed circuit board layers is between 0.15 mm and 0.5 mm to ensure reliable isolation between the first coil unit and the second coil unit.

[0016] The dependent claims describe preferred embodiments of the invention.

[0017] Preferably, the first inner contact and / or the second inner contact have a through-hole for electrical contact via an outer layer. Through-holes facilitate easy contacting of the wake-up coil.

[0018] Preferably, the second coil unit comprises a third winding, which is arranged in a third printed circuit board layer overlapping the second winding and electrically connected to the second winding. The electrical connection is preferably made by means of a via. By providing the third winding, energy can be transferred more efficiently from the first coil unit to the second coil unit to wake up the electrical device.

[0019] Preferably, the winding direction of the third winding is opposite to the winding direction of the second winding. This allows an inner contact of the second winding to be easily connected to an inner contact of the third winding, or an outer contact of the second winding to an outer contact of the third winding, without the induced voltages in the second and third windings canceling each other out.

[0020] Particularly preferably, the second coil unit comprises a fourth winding arranged in a fourth printed circuit board layer overlapping the third winding and electrically connected to the third winding, the third printed circuit board layer being arranged between the second and fourth printed circuit board layers. This further increases the efficiency of the wake-up coil. The further increase in efficiency can be seen, for example, in R.414789.

[0021] - 4 - enable a reduced size of the coil area, thereby reducing the circuit board area of ​​the wake-up coil.

[0022] The first printed circuit board layer is preferably arranged between the second and fourth printed circuit board layers. The first printed circuit board layer can be arranged between the second and third printed circuit board layers, or between the third and fourth printed circuit board layers. Arranging the first coil unit within the windings of the second coil unit can improve the efficiency of the transmitted electrical energy and thus enable a more compact design.

[0023] The second and third windings are preferably electrically connected to each other by means of a through-hole connection in the second contact area outside the second winding and outside the third winding, respectively. The third and fourth windings are preferably electrically connected to each other by means of a through-hole connection in the second contact area inside the third winding and within the fourth winding, respectively. The winding direction of the fourth winding preferably corresponds to the winding direction of the second winding and is opposite to the winding direction of the third winding. This allows the windings to be easily connected to each other in a compact design.Preferably, the second coil unit of the wake-up coil has a plurality of further windings which alternately have opposite winding directions and are arranged overlapping each other, wherein the electrical contacting of the windings is carried out by means of a through-hole connection of the inner contacts and the outer contacts in the second contacting area.

[0024] The first coil section and the second coil section are preferably rectangular, particularly square. This can allow for a more compact design of the first coil section and the second coil section.

[0025] Preferably, the first contact area is arranged at a first end of a longitudinal axis of the wake-up coil, and the second contact area is arranged at an opposite second end of the longitudinal axis. The opposite arrangement of the first and second contact areas results in a maximization of the creepage distance R.414789

[0026] - 5 - between the contact areas and can therefore reliably minimize leakage currents between the two coil units even with a compact design of the wake-up coil.

[0027] The first coil unit is preferably configured to induce an electrical voltage between 4 V and 8 V in the second coil unit. In particular, the first coil unit can induce an electrical voltage of 6 V in the second coil unit. This allows a switching converter of an electrical device to be reliably controlled in order to wake the electrical device from a sleep state when the electrical device is connected to a voltage source. Furthermore, the geometry according to the invention enables the necessary creepage distances to be maintained in order to transmit electrical voltages of this magnitude.

[0028] Preferably, the first contact area is connected to the first coil area by means of a first connection area, and the second contact area is connected to the second coil area by means of a second connection area. Electrical conductors in the first and second connection areas are arranged parallel to each other. This allows the contact area to be located further away from the coil area, thereby increasing the creepage distance between the first and second contact areas.

[0029] Furthermore, the invention relates to an electrical device comprising the wake-up coil described above. Thus, the electrical device can be reliably woken up by means of a voltage induced in the wake-up coil, while maintaining a compact and cost-effective design.

[0030] Brief description of the drawings

[0031] An embodiment of the invention is described in detail below with reference to the accompanying drawings. The drawing shows:

[0032] Figure 1 is a schematic top view of an electrical device with a wake-up coil according to an embodiment of the invention and R.414789

[0033] - 6 -

[0034] Figure 2 shows an exploded view of the individual printed circuit board layers of the

[0035] Wake-up coil according to the embodiment of the invention.

[0036] Embodiments of the invention

[0037] Preferably, all identical components, elements and / or units in all figures are provided with the same reference numerals.

[0038] Below, with reference to Figures 1 and 2, an electrical device 100 with a wake-up coil 1 is described in detail.

[0039] Figure 1 shows a section of the electrical device 100 in the area of ​​the wake-up coil 1. The wake-up coil 1 comprises a first coil unit 10 and a second coil unit 20. A current through the first coil unit 10 can induce a voltage in the second coil unit 20 to wake up the electrical device 100.

[0040] The wake-up coil 1 is arranged on a multilayer printed circuit board 3, which is, for example, designed as an FF4 printed circuit board. The printed circuit board 3 has several circuit board layers on which electrically conductive geometries can be mounted to form the wake-up coil 1. The individual circuit board layers are insulated from each other and can be electrically connected to each other by means of vias 2.

[0041] The first coil unit 10 has a first winding 11 extending along a first printed circuit board layer E1 (shown in Figure 2). The first winding 11 has a contact area 12 for electrical contact. Furthermore, the first winding 11 has a first coil area 13 to generate an electromagnetic field that can induce a voltage in the second coil unit 20. Due to the planar winding, the first contact area 12 has a first inner contact 14 located inside the first winding 11 and a first outer contact 15 located outside the first winding 11. The first inner contact 14 and the first outer contact 15 can be electrically connected to an outer layer of the printed circuit board 3 via vias 2. R.414789

[0042] - 7 -

[0043] The second coil unit 20 has a second winding 21 extending in a second printed circuit board plane E2 (shown in Figure 2). The second coil unit 20 is arranged parallel to the first coil unit 10. The second coil unit 20 also has a second contact area 22 and a second coil area 23, the contact area 22 being configured to be connected to the electrical circuit of the electrical device 100. The second coil area 23 can induce a voltage in the second coil unit 20 based on the electromagnetic field generated by the first coil area 13.

[0044] The second contact area 22 has a second inner contact 24 inside the second winding 21 and a second outer contact 25 outside the second winding 21 to electrically contact the second winding 21. The first contact area 12 is arranged outside the first coil area 13, and the second contact area 22 is arranged outside the second coil area 23. The first coil area 13 and the second coil area 23 are arranged overlapping perpendicular to the first printed circuit board plane E1.

[0045] The wake-up coil 1 extends along a longitudinal axis XX, which is arranged parallel to the first printed circuit board plane E1. The first contact area 12 is arranged opposite the second contact area 22, with the first contact area 12 being located at a first end of the longitudinal axis XX and the second contact area 22 being located at a second end of the longitudinal axis XX. This results in a maximized creepage distance between the two contact areas 12 and 22, thus minimizing the probability of leakage currents and voltage flashovers.

[0046] The first winding 11 has five turns. The second winding 21 has ten turns.

[0047] The wake-up coil 1 has a width b along the longitudinal axis XX of 29.75 mm. The height h of the wake-up coil 1, measured perpendicular to the width b, is 9.68 mm. The height h corresponds to the height of the first and second coil sections 13 and 23. R.414789

[0048] - 8 -

[0049] The first contact area 12 is connected to the first coil area 13 by means of a first connection area 16. Furthermore, the second contact area 22 is connected to the second coil area 23 by means of a second connection area 26. The first connection area 16 and the second connection area 26 are characterized in that the electrical conductors in the first connection area 16 and in the second connection area 26 are arranged parallel to each other. This allows the distance between the first contact area 12 and the second contact area 22 to be increased.

[0050] An electrical voltage of 5 V at a frequency of several MHz is preferably applied to the first coil unit 10. This generates an alternating electromagnetic field that induces a voltage in the second coil unit 20 sufficient to wake the electrical device 100 from a sleep mode.

[0051] The first coil unit 10 has, in addition to the first winding 11, further windings which are arranged overlapping with the first winding 11 in different printed circuit board layers and are shown in detail in Figure 2. The windings are connected to each other by means of vias 2 to form a larger winding across several printed circuit board layers.

[0052] Figure 2 shows the first circuit board layer E1 with the first winding 11, the second circuit board layer E2 with the second winding 21, a third circuit board layer E3 with a third winding 31, and a fourth circuit board layer E4 with a fourth winding 41. The four circuit board layers E1, E2, E3, E4 are arranged in parallel and insulated from each other in the wake-up coil 1 and are protected from the environment by an upper and lower outer layer.

[0053] The second winding 21, the third winding 31 and the fourth winding 41 differ essentially in the winding direction and the structure of the second contact area 22. R.414789

[0054] - 9 -

[0055] The windings 21, 31, 41 of the second coil unit 20 have ten turns, while the first winding 11 of the first coil unit 10 has five turns.

[0056] The first coil area 13 of the first winding 11 and the respective second coil areas 23 of the second winding 21, third winding 31 and fourth winding 41 are square with rounded corners and have a similar width and height.

[0057] The first contact area 12 of the first winding 11 is essentially circular, while the second contact areas 22 of the second winding 21, third winding 31 and fourth winding 41 are essentially rectangular.

[0058] A first turn of the first winding 11 spirals from the first inner contact 14 in the first contact area 12 towards the first connection area 16 and the first coil area 13, and then back towards the first connection area 16 and the first contact area 12. A second turn of the first winding 11 then follows the same path outside the first turn. This continues until the first winding 11 ends at the first outer contact 15 and is electrically connected there by means of a via 2. The second winding 21, third winding 31, and fourth winding 41 are constructed similarly to the first winding 11.

[0059] In the second coil unit 20, the winding direction of adjacent windings alternates. The second winding 21 and the fourth winding 41 have the same winding direction, which is opposite to the winding direction of the third winding 31.

[0060] The second winding 21 and the third winding 31 are electrically connected to each other in the second contact area 22 outside the second winding 21 and outside the third winding 31 by means of a through-hole 2. Furthermore, the third winding 31 and the fourth winding 41 are electrically connected to each other in the second contact area 22 inside the third winding 31 and inside the fourth winding 41 by means of a through-hole 2. Thus, an electric current can flow in the second R.414789

[0061] - 10 -

[0062] In coil unit 20, current flows from a second inner contact 24 along the second winding 21 to a second outer contact 25. The second outer contact 25 of the second winding 21 is electrically connected to the second outer contact 25 of the third winding 31, so that the electric current in the third winding 31 can flow from the second outer contact 25 along the third winding 31 to the second inner contact 24 of the third winding 31. The second inner contact 24 of the third winding 31 is electrically connected to a second inner contact 24 of the fourth winding 41 by means of a via 2, so that current can flow from the second inner contact 24 along the fourth winding 41 to the second outer contact 25 of the fourth winding 41.An electrical voltage can be tapped between the second inner contact 24 of the second winding 21 and the second outer contact 25 of the fourth winding 41, which can wake up the electrical device 100.

[0063] The second coil unit 20 can have a plurality of further windings, wherein adjacent windings preferably have opposite winding directions. The first coil unit 10 can also have a plurality of windings, which are arranged overlapping between the windings of the second coil unit 20.

[0064] By dividing the coil units 10, 20 into a contact area 12, 22 and a coil area 13, 23, wherein the coil areas 13, 23 are arranged overlapping each other and the contact areas 12, 22 are arranged opposite each other, the necessary creepage distances between the two contact areas 12, 22 can be easily and cost-effectively achieved to induce a voltage in the second coil unit 20 by means of the first coil unit 10 in order to wake up the electrical device 100. Furthermore, the electrical circuit contacting the contact area 12, 22 can be brought close to it, since there is sufficient distance to the other circuit of the wake-up coil 1.

Claims

R.414789 - 11 - Claims 1. Wake-up coil for waking up an electrical device (100), comprising a first coil unit (10) with a first winding (11) extending in a first printed circuit board plane (E1) and a second coil unit (20) with a second winding (21) extending in a second printed circuit board plane (E2) arranged parallel to the first printed circuit board plane (E1), wherein the first coil unit (10) has a first contact area (12) and a first coil area (13), and wherein the second coil unit (20) has a second contact area (22) and a second coil area (23), wherein the first winding (11) in the first contacting area (12) has a first inner contact (14) inside the first winding (11) and a first outer contact (15) outside the first winding (11) to electrically contact the first winding (11), wherein the second winding (21) in the second contacting area (22) has a second inner contact (24) inside the second winding (21) and a second outer contact (25) outside the second winding (21) to electrically contact the second winding (21), wherein the first coil area (13) and the second coil area (23) are arranged overlapping perpendicular to the first printed circuit board plane (E1),wherein the first contact area (12) is arranged outside the first coil area (13) and wherein the second contact area (22) is arranged outside the second coil area (23) and wherein the first coil unit (10) is configured to induce a voltage in the second coil unit (20) by means of an electric current through the first winding (11) in order to wake up an electrical device (100). R.414789 - 12 - 2. Wake-up coil according to claim 1, wherein the first inner contact (14) and / or the second inner contact (24) have a through-hole (2) to be electrically contacted via an outer layer.

3. Wake-up coil according to one of the preceding claims, wherein the second coil unit (20) comprises a third winding (31) which is arranged in a third printed circuit board plane (E3) overlapping with the second winding (21) and is electrically connected to the second winding (21), in particular by means of a via (2).

4. Wake-up coil according to claim 3, wherein the winding direction of the third winding (31) is opposite to the winding direction of the second winding (21).

5. Wake-up coil according to one of claims 3 or 4, wherein the second coil unit comprises a fourth winding (41) which is arranged in a fourth printed circuit board level (E4) overlapping with the third winding (31) and is electrically connected to the third winding (31), wherein the third printed circuit board level (E3) is arranged between the second printed circuit board level (E2) and the fourth printed circuit board level (E4).

6. Wake-up coil according to claim 5, wherein the first printed circuit board level (E1) is arranged between the second printed circuit board level (E2) and the fourth printed circuit board level (E4).

7. Wake-up coil according to claim 5 or 6, wherein the second winding (21) and the third winding (31) are electrically connected to each other in the second contacting area (22) outside the second winding (21) and outside the third winding (31) by means of a through-hole connection (2), and wherein the third winding (31) and the fourth winding (41) are electrically connected to each other in the second contacting area (22) inside the third winding (31) and inside the fourth winding (41) by means of a through-hole connection (2).

8. Wake-up coil according to one of the preceding claims, wherein the first coil area (13) and the second coil area (23) are rectangular, in particular square. R.414789 - 13 - 9. Wake-up coil according to one of the preceding claims, wherein the first contacting area (12) is arranged at a first end of a longitudinal axis (XX) of the wake-up coil (1) and wherein the second contacting area (22) is arranged at an opposite second end of the longitudinal axis (XX).

10. Awakening coil according to one of the preceding claims, wherein the first coil unit (10) is configured to induce an electrical voltage between 4 V and 8 V in the second coil unit (20), in particular 6 V.

11. Wake-up coil according to one of the preceding claims, wherein the first contacting area (12) is connected to the first coil area (13) by means of a first connection area (16) and wherein the second contacting area (22) is connected to the second coil area (23) by means of a second connection area (26), wherein electrical conductors in the first connection area (16) and in the second connection area (26) are arranged parallel to each other.

12. Electrical device comprising a wake-up coil (1) according to any one of the preceding claims.

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