Power switch arrangement and method for operating a power switch arrangement

Abstract

A power switch arrangement (10) comprises an interface unit (11) and a power switch (12). The interface unit (11) has a first printed circuit board (13). A first coil (15) is located at the first printed circuit board (13). The power switch (12) has a second printed circuit board (14). A second coil (16) is located at the second printed circuit board (14). The first coil (15) and the second coil (16) are aligned to each other. Furthermore, a method for operating a power switch arrangement (10) is disclosed.

Description

[0001] P2024,0741 WO N / P24-1300WO01 September 9, 2025- 1 -Description POWER SWITCH ARRANGEMENT AND METHOD FOR OPERATING A POWER SWITCH ARRANGEMENT The disclosure relates to a power switch arrangement and a method for operating a power switch arrangement.Document WO 2023 / 179915 A1 refers to a data interface for acircuit breaker. A wireless communication and a powertransfer from an interface unit to the circuit breaker isperformed. It is an objective to provide a power switch arrangement and a method for operating a power switch arrangement whichrealize a wireless power transfer between units of the powerswitch arrangement. This objective is achieved by the subject matter of the independent claims. Further developments and embodiments are described in the dependent claims.In an embodiment, a power switch arrangement comprises aninterface unit and a power switch. The interface unitcomprises a first printed circuit board. A first coil islocated at the first printed circuit board. The power switchcomprises a second printed circuit board. A second coil islocated at the second printed circuit board. The first coiland the second coil are aligned to each other. In an example, the power switch arrangement performs awireless power transfer, abbreviated WPT, by means of thefirst and the second coil. The power switch arrangementP2024,0741 WO N / P24-1300WO01 September 9, 2025- 2 -realizes an inductive power transfer between the first coiland the second coil. The first coil and the second coilimplement coupled inductors.In an embodiment of the power switch arrangement, the firstcoil and the second coil are realized by the first printedcircuit board, abbreviated first PCB, and the second printedcircuit board, abbreviated second PCB. Thus, the first andthe second coil are implemented by at least one conductive layer above or inside the first PCB and the second PCB. Alternatively, the first coil and the second coil arerealized by a first and a second device attached to the firstPCB and to the second PCB.In an embodiment, the power switch arrangement comprises a ferrite core configured to magnetically couple the first coil to the second coil.In an embodiment of the power switch arrangement, the firstPCB is parallel to the second PCB. The ferrite core isperpendicular to the first PCB and to the second PCB.In an embodiment of the power switch arrangement, a part of the ferrite core or the complete ferrite core is between thefirst PCB and the second PCB.In an embodiment of the power switch arrangement, the firstPCB comprises a first opening. The first coil encircles thefirst opening. The second PCB comprises a second opening. Thesecond coil encircles the second opening. The ferrite core isarranged in the first opening and in the second opening. Forexample, the first opening has a shape of a group consisting of a circle, a rectangle, a square, a triangle and a shapeP2024,0741 WO N / P24-1300WO01 September 9, 2025- 3 -with rounded corners. For example, the second opening has ashape of a group consisting of a circle, a rectangle, a square, a triangle and a shape with rounded corners. In an alternative embodiment of the power switch arrangement,only one PCB of the first PCB and the second PCB comprises anopening. In an embodiment of the power switch arrangement, the first coil and the second coil realize coupled inductors on a common core. Advantageously, the ferrite core improves the efficiency of WPT. In an example, the ferrite core is made of a soft magnetic material or a soft ferrite. Ferrites are usually ferrimagnetic ceramic compounds derived from iron oxides and additionally containing nickel, zinc, cobalt and / or manganese compounds. In an embodiment of the power switch arrangement, the ferritecore has the form of a cylinder or a rectangular cuboid. Theferrite core can be named ferrite rod. In an embodiment of the power switch arrangement, the first coil is realized by a conductive layer of the first PCB. Thefirst coil has a spiral shape in a top view on the first PCB.The second coil is realized by a conductive layer of thesecond PCB. The second coil has a spiral shape in a top viewon the second PCB. In an embodiment of the power switch arrangement, the spiral shape is designed e.g. as a spiral circular shape, a spiralP2024,0741 WO N / P24-1300WO01 September 9, 2025- 4 -quadratic shape or a spiral hexagonal shape. The conductive layer is e.g. made of copper. In an embodiment of the power switch arrangement, the first coil and the second coil are formed to enclose a shape of a group consisting of a circle, a rectangle, a square, a triangle and a shape with rounded corners. In an example, the first coil and the second coil are realized as planar coils. Advantageously, the two coils can be easily produced; they are low cost coils; they can easily be integrated with other electronic parts which are placed onthe first PCB and the second PCB.In an embodiment of the power switch arrangement, the firstPCB comprises a first number N1 of conductive layers withN1>1 or N1≥1. The first coil comprises conducting lines ineach conductive layer of the first number N1 of conductivelayers. The second PCB comprises a second number N2 ofconductive layers with N2>1 or N2≥1. The second coilcomprises conducting lines in each conductive layer of thesecond number N2 of conductive layers. N1 and N2 may be equalor unequal. In an example, N1=N2 or N1>N2 or N1≥N2 or N1<N2or N1≤N2. Typically, the first number N1 is in a rangebetween 1 and 20, alternatively in a range between 4 and 10. Typically, the second number N2 is in a range between 1 and 20, alternatively in a range between 4 and 10. Thus, in an example, the first and the second PCB are implemented as multi-layered PCBs. In an embodiment of the power switch arrangement, the conducting lines in the first number N1 of conductive layersP2024,0741 WO N / P24-1300WO01 September 9, 2025- 5 -are serially connected, in case N1>1. The conducting lines inthe second number N2 of conductive layers are seriallyconnected, in case N2>1. In an example, the first coil and the second coil are realized identically or differently. In an embodiment of the power switch arrangement, the number of windings of the first coil is W1 and the number ofwindings of the second coil is W2. In case the first or thesecond coil comprises conducting lines in more than oneconductive layer, W1 or W2 is the sum of the number ofwindings in the different layers. Thus, for example, W1=W2 orW1>W2 or W1≥W2 or W1<W2 or W1≤W2. Thus, a turn ratio equals 1or does not equal 1. In an embodiment of the power switch arrangement, the first coil is realized as a first device that is attached to the first PCB. The first coil comprises a wire that is wound around a first cylinder. The second coil is realized as asecond device that is attached to the second PCB. The secondcoil comprises a wire that is wound around a second cylinder. The first device and the second device are discrete devices. The first device and the second device are external devices with respect to the first PCB and the second PCB.In an example, the cylinder is a hollow cylinder, e.g. aright circular hollow cylinder. The first and the seconddevice are e.g. encapsulated coils.In an embodiment of the power switch arrangement, the firstdevice and the second device are implemented as Litz wire coils. A Litz wire coil uses a Litz wire which is a type ofP2024,0741 WO N / P24-1300WO01 September 9, 2025- 6 -multistrand wire or cable used to carry alternating currentat radio frequencies. The Litz wire is configured to reducethe skin effect and proximity effect losses in conductors used at frequencies up to about 1 MHz. In an embodiment of the power switch arrangement, the firstand the second device have openings to insert the ferritecore, described above. In an embodiment of the power switch arrangement, terminals of the first coil are fixed to through-holes of the first PCB or to solder pads of the first PCB. Terminals of the secondcoil are fixed to through-holes of the second PCB or tosolder pads of the second PCB. In an embodiment of the power switch arrangement, the interface unit comprises a first plastic housing. The firstPCB is enclosed by the first plastic housing. The powerswitch comprises a second plastic housing. The second PCB isenclosed by the second plastic housing. Advantageously,conductors of the power switch are electrically isolated from circuits of the interface unit. In an example, the first and the second plastic housing are realized such that a gap between the first coil and thesecond coil is kept small, for achieving a high efficiency ofWPT. In an embodiment, the power switch arrangement is configured for power transfer from the interface unit to the power switch.P2024,0741 WO N / P24-1300WO01 September 9, 2025- 7 -In an embodiment of the power switch arrangement, the power switch is a device of a group consisting of a circuitbreaker, a contactor and a motor starter. For example, thecircuit breaker is implemented as molded case circuit breaker, abbreviated MCCB. In an embodiment of the power switch arrangement, the interface unit comprises a first ferrite backing plate. Thepower switch comprises a second ferrite backing plate. Astack is formed with the following order of parts: the first ferrite backing plate / the first PCB / the second PCB / the secondferrite backing plate. Advantageously, the first and thesecond backing plates improve the efficiency of WPT and a shielding of the magnetic field towards other electronic parts in vicinity of the first and the second coil. In an embodiment, a method for operating a power switch arrangement comprises- providing a first AC current to a first coil that islocated at a first PCB of an interface unit, andgenerating an electromagnetic field by the first ACcurrent,- converting the electromagnetic field into a second ACcurrent in a second coil that is located at a second PCB of a power switch, wherein the first coil and the second coil are aligned to each other. Advantageously, an inductive power transfer between the first coil and the second coil is performed. The power switch arrangement described above is particularly suitable for the method for operating a power switch arrangement. Features described in connection with the powerP2024,0741 WO N / P24-1300WO01 September 9, 2025- 8 -switch arrangement can therefore be used for the method and vice versa.The method further comprises guiding the electromagneticfield between the first coil and the second coil by a ferritecore. In an embodiment of the power switch arrangement, a frequency of the first AC current is in a range between 10 kHz to 100MHz or alternatively in a range between 100 kHz and 10 MHz.In an example, the frequency is 200 kHz or 6.78 MHz or 13.56MHz. In an example, the power switch arrangement realizes a wireless power supply for a circuit breaker with coilsrealized directly on PCB. A power transfer is based on coils.These coils are realized directly on or in the PCBs byconductive layers which are part of the PCBs. In case thecoils are realized directly on or in the PCBs, no external devices for realization of the coils are needed, because the coils are already part of the PCBs. Optionally, to improve coupling between the coils, a ferritecore is added.In an example, at least two coils are used for WPT. Thesecoils can be fabricated directly on PCB and a ferrite core(rod) can be used to improve coupling. This assembly isimplemented for powering up a circuit breaker and keep atripping unit insulated. The circuit breaker can implementWPT together with optical communication. Thus, safety insulation requirements can be fulfilled. The assembly of thecoils is kept robust to tolerate displacement of these coils.A possible and cost effective solution is to realize coilsP2024,0741 WO N / P24-1300WO01 September 9, 2025- 9 -directly on PCB instead of coils as parts delivered from some supplier. To improve coupling and to be more independent on a distance between the two coils, a ferrite rod can be added. The following description of figures of embodiments shall further illustrate and explain aspects of the power switch arrangement and of the method for operating the power switch. Parts and components with the same structure and the same effect respectively appear with equivalent reference symbols. As far as parts and components correspond to one another interms of their function in different figures, the descriptionthereof is not repeated for each of the subsequent figures. Figures 1A and 1B show an example of a power switch arrangement; Figures 2 to 4 show further examples of a power switch arrangement; and Figure 5 shows an example of a multi-layered printed circuit board. Figures 1A and 1B show an example of a power switcharrangement 10. The power switch arrangement 10 comprises aninterface unit 11 with a first printed circuit board 13. A printed circuit board can be abbreviated PCB. A first coil 15is located at the first PCB 13. Moreover, the power switcharrangement 10 comprises a power switch 12 with a second PCB14. A second coil 16 is located at the second PCB 14. Thefirst coil 15 and the second coil 16 are aligned to each other. The power switch arrangement 10 comprises a ferrite core 17that magnetically couples the first coil 15 to the secondP2024,0741 WO N / P24-1300WO01 September 9, 2025- 10 -coil 16. The first PCB 13 is parallel to the second PCB 14.The ferrite core 17 is perpendicular to the first PCB 13 andto the second PCB 14.The first PCB 13 comprises a first opening 18. The first coil15 encircles the first opening 18. The second PCB 14comprises a second opening 19. The second coil 16 encircles the second opening 19. The ferrite core 18 is arranged in the first opening 18 and in the second opening 19. The interface unit 11 comprises a first plastic housing 41. The power switch 12 comprises a second plastic housing 42.The first PCB 13 is inside the first plastic housing 41. Thesecond PCB 14 is inside the second plastic housing 42. Theferrite core 17 is enclosed in the first plastic housing 41.Thus, the first plastic housing 41 protrudes into the secondplastic housing 42. As shown in Figure 1B, the first coil 15 is realized by aconductive layer of the first PCB 13 and has a spiral shape.Also the second coil 16 is realized by a conductive layer ofthe second PCB 14 and has a spiral shape.The power switch arrangement 10 is operated as follows: Afirst AC current I1 is applied to the first coil 15. Thefirst AC current I1 generates an electromagnetic field. Theelectromagnetic field is converted into a second AC currentI2 by the second coil 16. The electromagnetic field is guidedbetween the first coil 15 and the second coil 16 by the ferrite core 17. In an alternative embodiment, not shown, the first opening 18 and / or the second opening 19 are omitted.P2024,0741 WO N / P24-1300WO01 September 9, 2025- 11 -In an alternative embodiment, not shown, the ferrite core 17is enclosed in the second plastic housing 42. Thus, thesecond plastic housing 42 protrudes into the first plastichousing 41. Figure 2 shows a further example of a power switch arrangement 10 which is a further development of the embodiment shown in Figures 1A and 1B. The first coil 15 is realized as a first device 31. The second coil 16 is realized as a second device 32. The first device 31 is attached to thefirst PCB 13. The second device 32 is attached to the secondPCB 14. The first device 31 comprises a wire that is woundaround a first cylinder. The second device 32 comprises awire that is wound around a second cylinder. For example, thefirst device 31 and the second device 32 are implemented as Litz wire coils. Such devices 31, 32 can be designed and fabricated fulfilling criteria e.g. regarding coupling efficiency and space, in case they are not available on the market. Figure 3 shows a further example of a power switcharrangements 10 which is a further development of theembodiment shown in Figures 1A, 1B and 2. The interface unit11 comprises a first ferrite backing plate 43. The powerswitch 12 comprises a second ferrite backing plate 44. Astack is formed with the following order of parts: the firstferrite backing plate 43 / the first PCB 13 / the second PCB14 / the second ferrite backing plate 44. Optionally, the firstferrite backing plate 43 and the ferrite core 17 are realizedas one piece. In an alternative embodiment, not shown, the ferrite core 17 and the first and the second openings 18, 19 are omitted.P2024,0741 WO N / P24-1300WO01 September 9, 2025- 12 -Figure 4 shows a further example of a power switch arrangement 10 which is a further development of theembodiments shown in Figures 1A, 1B, 2 and 3. The powerswitch arrangement 10 is configured to transfer electrical power from the interface unit 11 to the power switch 12. The power switch 12 is realized as a circuit breaker 45.The interface unit 11 comprises a DC-to-AC converter 51 whichis connected to the first coil 15. The first AC current I1 isprovided from the DC-to-AC converter 51 to the first coil 13. The DC-to-AC converter 51 is connected to a first control circuit 52 of the interface unit 11. The interface unit 11 comprises a light source 53 and a light sensor 54.The power switch 12 comprises an AC-to-DC converter 61 thatis connected to the second coil 16. The second coil 16provides a second AC current I2 to the AC-to-DC converter 61.The AC-to-DC converter 61 provides electrical power to asecond control circuit 62 of the power switch 12. The power switch 12 comprises a light sensor 63 and a light source 64. The light source 53 of the interface unit 11 and the light sensor 63 of the power switch 12 form a first opto-isolator.An opto-isolator can also be named opto-coupler. The lightsensor 54 of the interface unit 11 and the light source 64 ofthe power switch 12 form of a second opto-isolator. Thus, thefirst control circuit 52 and the second control circuit 62are configured to bidirectionally communicate via the first and the second opto-isolator. In case the power switch 12 is implemented as a circuit breaker, the power switch 12 comprises a first fixed terminal 66, a second fixed terminal 67, a contact bridge 68 and an actuator 65. The actuator 65 is controlled by the secondP2024,0741 WO N / P24-1300WO01 September 9, 2025- 13 -control circuit 62. The actuator 65 is configured to move the contact bridge 68 in order to provide an electrically contact between the first fixed terminal 66 and the second fixedterminal 67 or to interrupt an electrical current flowingbetween the first fixed terminal 66 and the second fixed terminal 67. Advantageously, the second control circuit 62 ofthe power switch 12 is supplied with electrical power by theinterface unit 11, even in case no electrical power is provided to the first fixed terminal 66 or to the second fixed terminal 67.Figure 5 shows an example of a multi-layered PCB. The firstPCB 13 comprises a first number N1 of conductive layers 71 to74 with N1>1. In the example, shown in Figure 5, the first number N1 is 4. The first coil 15 comprises conducting lines in each conductive layer of the first number N1 of conductivelayers 71 to 74. The first PCB 13 has the first opening 18,realized as a through hole. The conducting lines in the first number N1 of conductive layers 71 to 74 are seriallyconnected (not shown in Figure 5). The first PCB 13 comprisesa first core 75 and a second core 76 which are connected to each other by a prepreg layer 77.The second PCB 14 and the second coil 16 are implemented suchas the first PCB 13 and the first coil 15, as describedabove. The second PCB 14 comprises a second number N2 ofconductive layers with N2>1. The second coil 16 comprises conducting lines in each conductive layer of the secondnumber N2 of conductive layers. The conducting lines in thesecond number N2 of conductive layers are serially connected. The second PCB 14 has the second opening 19, realized as a through hole.P2024,0741 WO N / P24-1300WO01 September 9, 2025- 14 -In Figure 5, only an example of a multi-layered PCB is shown. There are alternative embodiments for the realization of amulti-layered PCB with four conductive layers. Alternatively,the first number N1 is in a range 20 ≥ N1 ≥ 4 or N1 = 6 or 10≥ N1 ≥ 6. Correspondingly, the second number N2 is in a range20 ≥ N2 ≥ 4 or N2 = 6 or 10 ≥ N2 ≥ 6.The embodiments shown in Figures 1A to 5 as stated represent example embodiments of an arrangement 10; therefore, they do not constitute a complete list of all embodiments according to the arrangement 10. Actual arrangements may vary from the embodiments shown in terms of parts, devices and circuits, for example.

[0002] P2024,0741 WO N / P24-1300WO01 September 9, 2025- 15 -Reference numerals10 power switch arrangement11 interface unit12 power switch13 first printed circuit board14 second printed circuit board15 first coil16 second coil17 ferrite core18 first opening19 second opening31 first device32 second device41 first plastic housing42 second plastic housing43 first ferrite backing plate44 second ferrite backing plate45 circuit breaker51 DC-to-AC converter52 first control circuit53 light source54 light sensor61 AC-to-DC converter62 second control circuit63 light sensor64 light source65 actuator66 first fixed terminal67 second fixed terminal68 contact bridge71 to 74 conductive layer75, 76 coreP2024,0741 WO N / P24-1300WO01 September 9, 2025- 16 -77 prepreg layerI1 first AC currentI2 second AC current

Claims

P2024,0741 WO N / P24-1300WO01 September 9, 2025- 17 -Claims1. A power switch arrangement (10), comprising- an interface unit (11) with a first printed circuit board(13), wherein a first coil (15) is located at the firstprinted circuit board (13), and- a power switch (12) with a second printed circuit board(14), wherein a second coil (16) is located at the secondprinted circuit board (14), wherein the first coil (15) and the second coil (16) arealigned to each other.

2. The power switch arrangement (10) of claim 1,wherein the power switch arrangement (10) further comprises aferrite core (17) configured to magnetically couple the firstcoil (15) to the second coil (16).

3. The power switch arrangement (10) of claim 2,wherein the first printed circuit board (13) is parallel tothe second printed circuit board (14), and wherein the ferrite core (17) is perpendicular to the firstprinted circuit board (13) and to the second printed circuitboard (14).

4. The power switch arrangement (10) of claims 2 or 3,wherein the first printed circuit board (13) comprises afirst opening (18),wherein the first coil (15) encircles the first opening (18),wherein the second printed circuit board (14) comprises asecond opening (19),wherein the second coil (16) encircles the second openingP2024,0741 WO N / P24-1300WO01 September 9, 2025- 18 -wherein the ferrite core (18) is arranged in the firstopening (18) and in the second opening (19).

5. The power switch arrangement (10) of any one of claims 1to 4,wherein the first coil (15) is realized by a conductive layer(71) of the first printed circuit board (13) and has a spiralshape, andwherein the second coil (16) is realized by a conductivelayer of the second printed circuit board (14) and has aspiral shape.

6. The power switch arrangement (10) of claim 5,wherein the first printed circuit board (13) comprises afirst number N1 of conductive layers (71 to 74) with N1>1,wherein the first coil (15) comprises conducting lines ineach conductive layer of the first number N1 of conductivelayers (71 to 74),wherein the second printed circuit board (14) comprises asecond number N2 of conductive layers with N2>1, andwherein the second coil (16) comprises conducting lines ineach conductive layer of the second number N2 of conductive layers.

7. The power switch arrangement (10) of claim 6,wherein the conducting lines in the first number N1 of conductive layers (71 to 74) are serially connected, and wherein the conducting lines in the second number N2 of conductive layers are serially connected.

8. The power switch arrangement (10) of any one of claims 1to 4,P2024,0741 WO N / P24-1300WO01 September 9, 2025- 19 -wherein the first coil (15) is realized as a first device(31) that is attached to the first printed circuit board (13) and comprises a wire that is wound around a first cylinder,wherein the second coil (16) is realized as a second device(32) that is attached to the second printed circuit board(14) and comprises a wire that is wound around a secondcylinder.

9. The power switch arrangement (10) of any one of claims 1to 8, wherein the interface unit (11) further comprises a firstplastic housing (41),wherein the first printed circuit board (13) is enclosed bythe first plastic housing (41),wherein the power switch (12) further comprises a secondplastic housing (42), andwherein the second printed circuit board (14) is enclosed bythe second plastic housing (42).

10. The power switch arrangement (10) of any one of claims 1to 9,wherein the power switch arrangement (10) is configured forpower transfer from the interface unit (11) to the powerswitch (12).

11. The power switch arrangement (10) of any one of claims 1to 10, wherein the power switch (12) is a device of a groupconsisting of a circuit breaker (45), a contactor and a motorstarter.

12. A method for operating a power switch arrangement (10), comprisingP2024,0741 WO N / P24-1300WO01 September 9, 2025- 20 -- providing a first AC current (I1) to a first coil (15)that is located at a first printed circuit board (13) ofan interface unit (11), and generating an electromagneticfield by the first AC current (I1),- converting the electromagnetic field into a second ACcurrent (I2) by a second coil (16) that is located at asecond printed circuit board (14) of a power switch (12),wherein the first coil (15) and the second coil (16) arealigned to each other.

13. The method of claim 12, wherein the method further comprises:- guiding the electromagnetic field between the first coil(15) and the second coil (16) by a ferrite core (17).

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