CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Chinese Patent Application No.CN201610715191.9 filed on August 24, 2016 and Chinese Patent Application No. CN201610717603.2 filed on August 24, 2016 in the State Intellectual Property Office of China, the whole disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention The present invention relates to a wireless power supply device and an electrical apparatus comprising the wireless power supply device.

Description of the Related Art

In the prior art, an electric energy for control and driving parts of an electrical apparatus is mainly transmitted by electrical wires connected to an external power source or a built-in battery. That is, the internal power transmission of the electrical apparatus is mainly achieved by physical connections of the electrical wires. Thereby, the electrical wires may be physically worn and damaged by some movable parts of the electrical apparatus, and it may lead to some safety problems and reduce the life of the electrical apparatus. As a result, it needs to often maintain the electrical apparatus.

In order to overcome the problems due to the physical connections of electrical wires, in recent years, a wireless power supply device has been introduced into the electrical apparatus. The wireless power supply device may achieve the electric energy contactless transmission by coupling coils among some parts in the electrical apparatus. Thereby, the movable parts of the electrical apparatus are not limited to the electrical wires, and may be positioned at any suitable locations. As a result, it may completely avoid the above problems caused by the physical connections of electrical wires. Moreover, it may greatly increase the freedom of the structural design of the electrical apparatus, and improve the aesthetic feeling and the functions of the electrical apparatus, especially the household electrical appliances.

In the prior art, the wireless power supply device generally comprises a transmitting coil and a receiving coil electromagnetically coupled with the transmitting coil. In practical use, for ensuring the beauty appearance of the electrical apparatus, it is necessary to hide the transmitting coil in a metal case. If the metal case is close to the transmitting coil, an alternating magnetic field generated by the transmitting coil may induce an eddy current in the surface of the metal case, which is referred as the eddy current effect. As we all know, due to the eddy current effect, the power of the electrical system is wasted on the heating of the metal case, which reduces the efficiency and stability of the electrical system; and the inductance of the transmitting coil and the receiving coil, as well as the mutual inductance between the transmitting coil and the receiving coil, is affected, and the original matching between the transmitting coil and the receiving coil may become invalid, causing the electrical system cannot work normally.

In order to reduce the eddy current effect, it usually requires keeping the distance between the metal case and the receiving coil by at least 6mm, which may increase the size of the metal case and the electrical apparatus, and increase the difficulty of the appearance design of the electrical apparatus.

SUMMARY OF THE INVENTION

The present invention has been made to overcome or alleviate at least one aspect of the above mentioned disadvantages.

According to an aspect of the present invention, there is provided a wireless power supply device comprising a transmitting coil assembly and a receiving coil assembly. The transmitting coil assembly comprising: a first ferrite core having a receiving chamber with an opening; and a transmitting coil provided in the receiving chamber of the first ferrite core. The receiving coil assembly is adapted to be moved into the receiving chamber through the opening of the receiving chamber and located at a predetermined position in the receiving chamber, so as to be electromagnetically coupled with the transmitting coil assembly.

According to an exemplary embodiment of the present invention, the transmitting coil comprises a first sub transmitting coil and a second sub transmitting coil spaced from and facing the first sub transmitting coil; and the first sub transmitting coil and the second sub transmitting coil are adapted to produce magnetic fields with the same direction.

According to another exemplary embodiment of the present invention, the first sub transmitting coil and the second sub transmitting coil are connected in serials and wound in the same direction, so that the direction of the magnetic field generated by a current flowing through the first sub transmitting coil is the same as the direction of the magnetic field generated by a current flowing through the second sub transmitting coil.

According to another exemplary embodiment of the present invention, the first ferrite core comprises a bottom wall, and a first side wall and a second side wall at both sides of the bottom wall; a first protrusion is formed on an inner side of the first side wall, a second protrusion is formed on an inner side of the second side wall; and the first sub transmitting coil is wound on the first protrusion, the second sub transmitting coil is wound on the second protrusion.

According to another exemplary embodiment of the present invention, the wireless power supply device further comprises a metal case formed with an inside space into which the transmitting coil assembly is adapted to be received.

According to another exemplary embodiment of the present invention, a window is formed in a top wall of the metal case, the opening of the receiving chamber of the first ferrite core faces the window, so that the receiving coil assembly is adapted to be moved into the receiving chamber through the window of the metal case and the opening of the receiving chamber.

According to another exemplary embodiment of the present invention, the metal case has a bottom opening, so that the transmitting coil assembly is adapted to be moved into the inside space of the metal case through the bottom opening.

According to another exemplary embodiment of the present invention, when the receiving coil assembly is moved into and located at the predetermined position in the receiving chamber, the receiving coil assembly is positioned between the first sub transmitting coil and the second sub transmitting coil.

According to another exemplary embodiment of the present invention, the receiving coil assembly comprises a second ferrite core and a receiving coil wound on the second ferrite core.

According to another exemplary embodiment of the present invention, when the receiving coil assembly is moved into and located at the predetermined position in the receiving chamber, a center axis of the transmitting coil is parallel to a center axis of the receiving coil.

According to another exemplary embodiment of the present invention, when the receiving coil assembly is moved into and located at the predetermined position in the receiving chamber, the transmitting coil and the receiving coil have a common center axis.

According to another exemplary embodiment of the present invention, the first protrusion and the second protrusion of the first ferrite core exhibits a cuboid shape or a cylinder shape, the first sub transmitting coil and the second sub transmitting coil are wound on the peripheral surface of the first protrusion and the peripheral surface of the second protrusion, respectively.

According to another exemplary embodiment of the present invention, the second ferrite core exhibits a cuboid shape or a cylinder shape and has a top surface, a bottom surface and a peripheral surface between the top surface and the bottom surface, and the receiving coil is wound on the peripheral surface of the second ferrite core.

According to another exemplary embodiment of the present invention, the first ferrite core is an elongated ferrite core with a substantially U-shaped cross-section. According to another exemplary embodiment of the present invention, the metal case has a cross section substantially exhibiting an inverted-U shape.

According to another exemplary embodiment of the present invention, a length of the transmitting coil assembly is longer than a length of the receiving coil assembly, so that a plurality of receiving coil assemblies are adapted to be received in different locations in a single transmitting coil assembly at the same time, and electromagnetically coupled with the single transmitting coil assembly at the same time.

According to another exemplary embodiment of the present invention, a plurality of windows are formed in the top wall of the metal case, and the plurality of receiving coil assemblies are adapted to be moved into the metal case through the plurality of windows, respectively, and electromagnetically coupled with the single transmitting coil assembly provided in the metal case.

According to another aspect of the present invention, there is provided a wireless power supply device, comprising: a transmitting coil; a receiving coil assembly; and a ferrite electromagnetic shielding member having a receiving chamber into which the transmitting coil is received. A first window is formed in a top wall of the ferrite electromagnetic shielding member, and the receiving coil assembly is adapted to be moved into the receiving chamber through the first window and located at a predetermined position in the receiving chamber, so as to electromagnetically coupled with the transmitting coil.

According to an exemplary embodiment of the present invention, the wireless power supply device further comprises a metal case having an inside space into which the ferrite electromagnetic shielding member is adapted to be received, a second window corresponding to the first window is formed in the top wall of the metal case, and the receiving coil assembly is adapted to be moved into the receiving chamber through the first window and the second window.

According to another exemplary embodiment of the present invention, the receiving coil assembly comprises a ferrite core and a receiving coil wound on the ferrite core.

According to another exemplary embodiment of the present invention, when the receiving coil assembly is moved into and located at the predetermined position in the receiving chamber, a center axis of the transmitting coil is parallel to a center axis of the receiving coil.

According to another exemplary embodiment of the present invention, the metal case further comprises a pair of side walls at both sides of the top wall thereof, the inside space is defined by the top wall and the pair of side walls of the metal case.

According to another exemplary embodiment of the present invention, the ferrite electromagnetic shielding member further comprises a pair of side walls at both sides of the top wall thereof, the receiving chamber is defined by the top wall and the pair of side walls of the ferrite electromagnetic shielding member. According to another exemplary embodiment of the present invention, the ferrite core exhibits a cuboid shape and has a top surface, a bottom surface and a peripheral surface between the top surface and the bottom surface, the receiving coil is wound on the peripheral surface of the ferrite core.

According to another exemplary embodiment of the present invention, the transmitting coil is a hollow rectangular coil.

According to another exemplary embodiment of the present invention, a length of the transmitting coil is longer than a length of the receiving coil, so that a plurality of receiving coils are adapted to be received in different locations in a single transmitting coil in the length direction of the transmitting coil at the same time, and electromagnetically coupled with the single transmitting coil assembly at the same time.

According to another exemplary embodiment of the present invention, a plurality of first windows are formed in the top wall of the ferrite electromagnetic shielding member; a plurality of second windows corresponding to the plurality of first windows, respectively, are formed in the top wall of the metal case. The plurality of receiving coil assemblies are adapted to be moved into the receiving chamber through the plurality of first windows and the plurality of second windows, and electromagnetically coupled with the single transmitting coil provided in the receiving chamber.

According to another aspect of the present invention, there is provided an electrical apparatus comprising: a load; and the above wireless power supply device.

In some exemplary embodiments of the present invention, most of the magnetic field generated by the transmitting coil is confined in the receiving chamber of the first ferrite core, only a very small amount of the magnetic field is leaked outside the first ferrite core, thereby reducing the eddy current effect on the metal part (for example, the metal case) near the transmitting coil, and improving the efficiency and the stability of the wireless power supply.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings, in which:

Fig. l shows an illustrative exploded view of a wireless power supply device according to a first exemplary embodiment of the present invention;

Fig.2 shows a cross section view of a transmitting coil assembly of the wireless power supply device according to the first exemplary embodiment of the present invention;

Fig.3 shows an illustrative assembled view of the wireless power supply device according to the first exemplary embodiment of the present invention;

Fig.4 shows an illustrative perspective view of the wireless power supply device according to the first exemplary embodiment of the present invention;

Fig.5 shows a cross section view of the wireless power supply device according to the first exemplary embodiment of the present invention;

Fig.6 shows an illustrative exploded view of a wireless power supply device according to a second exemplary embodiment of the present invention;

Fig.7 shows an illustrative perspective view of a transmitting coil and a receiving coil assembly of the wireless power supply device of Fig.6;

Fig.8 shows an illustrative perspective view of the wireless power supply device according to the second exemplary embodiment of the present invention, wherein a ferrite electromagnetic shielding member is received in a metal case, the transmitting coil is received in the ferrite electromagnetic shielding member, the receiving coil assembly is not inserted into the metal case;

Fig.9 shows an illustrative perspective view of the wireless power supply device of

Fig.8;

Fig.10 shows an illustrative perspective view of the wireless power supply device according to the second exemplary embodiment of the present invention, wherein the ferrite electromagnetic shielding member is received in the metal case, the transmitting coil is received in the ferrite electromagnetic shielding member, the receiving coil assembly is inserted into the metal case;

Fig.11 shows an illustrative assembled view of the wireless power supply device of

Fig.10; and

Fig.12 shows an illustrative perspective view of the transmitting coil and the receiving coil assembly of the wireless power supply device of Fig.10.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE IVENTION

Exemplary embodiments of the present disclosure will be described hereinafter in detail with reference to the attached drawings, wherein the like reference numerals refer to the like elements. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those skilled in the art.

In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed

embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing. According to a general concept of the present invention, there is provided a wireless power supply device comprising a transmitting coil assembly and a receiving coil assembly. The transmitting coil assembly comprising: a first ferrite core having a receiving chamber with an opening; and a transmitting coil provided in the receiving chamber of the first ferrite core, wherein the receiving coil assembly is adapted to be moved into the receiving chamber through the opening of the receiving chamber and located at a predetermined position in the receiving chamber, so as to be electromagnetically coupled with the transmitting coil assembly.

According to another general concept of the present invention, there is provided a wireless power supply device, comprising: a transmitting coil; a receiving coil assembly; and a ferrite electromagnetic shielding member having a receiving chamber into which the transmitting coil is received, wherein a first window is formed in a top wall of the ferrite electromagnetic shielding member, the receiving coil assembly is adapted to be moved into the receiving chamber through the first window and located at a predetermined position in the receiving chamber, so as to be electromagnetically coupled with the transmitting coil.

First Embodiment

Figs.1-5 shows the wireless power supply device according to the first exemplary embodiment of the present invention. Hereafter, it will describe in detail the wireless power supply device with reference to Figs.1-5.

Fig. l shows an illustrative exploded view of the wireless power supply device according to the first exemplary embodiment of the present invention.

As shown in Fig.l, in an embodiment, the wireless power supply device mainly comprises a transmitting coil assembly 100 and a receiving coil assembly 200. The receiving coil assembly 200 is adapted to be electromagnetically coupled with the transmitting coil assembly 100.

Fig.2 shows a cross section view of the transmitting coil assembly 100 of the wireless power supply device according to the first exemplary embodiment of the present invention.

As shown in Figs.1-2, in an embodiment, the transmitting coil assembly 100 mainly comprises a first ferrite core 110 and a transmitting coil 120a, 120b. The first ferrite core 110 has a receiving chamber 101 with an opening. The transmitting coil 120a, 120b is provided in the receiving chamber 101 of the first ferrite core 110. The receiving coil assembly 200 is adapted to be moved into the receiving chamber 101 through the opening of the receiving chamber 101 and located at a predetermined position (see Figs.3-5) in the receiving chamber 101, so as to be electromagnetically coupled with the transmitting coil assembly 100.

As shown in Figs. l and 2, in an embodiment, the transmitting coil 120a, 120b comprises a first sub transmitting coil 120a and a second sub transmitting coil 120b spaced from and facing the first sub transmitting coil 120a. The first sub transmitting coil 120a and the second sub transmitting coil 120b are adapted to produce magnetic fields with the same direction.

As shown in Figs.1-2, in an embodiment, the first sub transmitting coil 120a and the second sub transmitting coil 120b are connected in serials and wound in the same direction, so that the direction of the magnetic field generated by a current flowing through the first sub transmitting coil 120a is the same as the direction of the magnetic field generated by a current flowing through the second sub transmitting coil 120b.

As shown in Figs.1-2, in an embodiment, the first ferrite core 110 comprises a bottom wall 113, a first side wall 111 and a second side wall 112 at both sides of the bottom wall 113. In the illustrated embodiment, the first ferrite core 110 does not have a top wall, that is, the first ferrite core 110 is opened at the top thereof. Thereby, the first ferrite core 110 is formed as an elongated ferrite core with a substantially U-shaped cross-section.

As shown in Figs.1-2, in an embodiment, a first protrusion 110a is formed on an inner side of the first side wall 111. A second protrusion 110b is formed on an inner side of the second side wall 112. The first sub transmitting coil 120a is wound on the first protrusion 110a. The second sub transmitting coil 120b is wound on the second protrusion 110b.

Fig.3 shows an illustrative assembled view of the wireless power supply device according to the first exemplary embodiment of the present invention; Fig.4 shows an illustrative perspective view of the wireless power supply device according to the first exemplary embodiment of the present invention; Fig.5 shows a cross section view of the wireless power supply device according to the first exemplary embodiment of the present invention.

As shown in Figs.l, 3-5, in an embodiment, the wireless power supply device may further comprise a metal case 300. The metal case 300 is formed with an inside space 301 into which the transmitting coil assembly 100 is adapted to be received.

As shown in Figs.l, 3-5, in an embodiment, a window 331 is formed in a top wall 330 of the metal case 300, the opening of the receiving chamber 101 of the first ferrite core 110 faces the window 331. Thereby, the receiving coil assembly 200 is adapted to be moved into the receiving chamber 101 through the window 331 of the metal case 300 and the opening of the receiving chamber 101 and located at a predetermined position in the receiving chamber 101, so as to be electromagnetically coupled with the transmitting coil assembly 100.

As shown in Figs. l, 3-5, in an embodiment, the metal case 300 has a bottom opening, so that the transmitting coil assembly 100 is adapted to be moved into the inside space 301 of the metal case 300 through the bottom opening.

As shown in Figs.1-5, in an embodiment, when the receiving coil assembly 200 is moved into and located at the predetermined position in the receiving chamber 101, the receiving coil assembly 200 is positioned between the first sub transmitting coil 120a and the second sub transmitting coil 120b.

As shown in Figs. l, 3-5, in an embodiment, the receiving coil assembly 200 comprises a second ferrite core 210 and a receiving coil 220 wound on the second ferrite core 210.

As shown in Figs.3-5, in an embodiment, when the receiving coil assembly 200 is moved into and located at the predetermined position in the receiving chamber 101, a center axis of the transmitting coil 120a, 120b is parallel to a center axis of the receiving coil 220.

As shown in Figs.3-5, in an embodiment, when the receiving coil assembly 200 is moved into and located at the predetermined position in the receiving chamber 101, the transmitting coil 120a, 120b and the receiving coil 220 have a common center axis.

As shown in Figs.1-5, in an embodiment, the first protrusion 110a and the second protrusion 110b of the first ferrite core 110 may exhibit a cuboid shape, a cylinder shape or any other suitable shape. The first sub transmitting coil 120a and the second sub transmitting coil 120b are wound on the peripheral surface of the first protrusion 110a and the peripheral surface of the second protrusion 110b, respectively.

As shown in Figs.l, 3-5, in an embodiment, the second ferrite core 210 may exhibit a cuboid shape, a cylinder shape or any other suitable shape. The second ferrite core 210 has a top surface, a bottom surface and a peripheral surface between the top surface and the bottom surface. The receiving coil 220 is wound on the peripheral surface of the second ferrite core 210.

As shown in Figs.l, 3-5, in an embodiment, the metal case 300 comprises a top wall 330 and a pair of side walls 310, 320 at both sides of the top wall 330. The metal case 300 does not have a bottom wall, that is, the metal case 300 is opened at the bottom side thereof. Thereby, in the illustrated embodiment, the metal case 300 has a cross section substantially exhibiting an inverted-U shape.

As shown in Figs. l, 3-4, in an embodiment, a length of the transmitting coil assembly 100 is longer than a length of the receiving coil assembly 200, so that a plurality of receiving coil assemblies 200 are adapted to be received in different locations in a single transmitting coil assembly 100 at the same time. In this way, the plurality of receiving coil assemblies 200 may be electromagnetically coupled with the single transmitting coil assembly 100 at the same time.

As shown in Figs. l, 3-4, in an embodiment, a plurality of windows 331 are formed in the top wall 330 of the metal case 300, the plurality of receiving coil assemblies 200 are adapted to be moved into the metal case 300 through the plurality of windows 331, respectively, and be electromagnetically coupled with the single transmitting coil assembly 100 provided in the metal case 300.

In an embodiment, the transmitting coil assembly 100 may be connected to a circuit board (not shown). The circuit board may have a DC- AC conversion circuit for converting a direct current into an alternating current. The alternating current from the DC-AC conversion circuit may flow through a matching circuit on the circuit board. Then, it may be used to drive the transmitting coil. The receiving coil assembly 200 may be connected to another circuit board (not shown). In order to drive a load, the other circuit board may have a matching circuit, a rectifier, a filter and a DC-DC conversion circuit.

Although it is not shown, in another embodiment of the present invention, there is also provided an electrical apparatus. The electrical apparatus may comprise a load and the above wireless power supply device configured to supply power to the load.

In an embodiment, the aforementioned electrical apparatus may comprise but not limit to a refrigerator, a washing machine, an air conditioners, etc.

Second Embodiment

Figs.6-12 shows the wireless power supply device according to the second exemplary embodiment of the present invention. Hereafter, it will describe in detail the wireless power supply device with reference to Figs.6- 12.

Fig.6 shows an illustrative exploded view of a wireless power supply device according to a second exemplary embodiment of the present invention; Fig.7 shows an illustrative perspective view of a transmitting coil 100' and a receiving coil assembly 200' of the wireless power supply device of Fig.6.

As shown in Figs.6-7, in an embodiment, the wireless power supply device mainly comprises a transmitting coil 100', and a receiving coil assembly 200' adapted to be electromagnetically coupled with the transmitting coil 100' .

As shown in Figs.6-7, in an embodiment, the wireless power supply device further comprises a ferrite electromagnetic shielding member 400' having a receiving chamber 40 into which the transmitting coil 100' is received.

As shown in Figs.6-7, in an embodiment, a first window 43 is formed in a top wall 430' of the ferrite electromagnetic shielding member 400', the receiving coil assembly 200' is adapted to be moved into the receiving chamber 40 through the first window 43 and located at a predetermined position in the receiving chamber 401 ', so as to be electromagnetically coupled with the transmitting coil 100' .

As shown in Figs.6-7, in an embodiment, the wireless power supply device may further comprise a metal case 300' having an inside space 301 ' into which the ferrite electromagnetic shielding member 400' is adapted to be received. In this way, the transmitting coil 100' may be hidden in the metal case 300', and it may improve the appearance of the wireless power supply device.

As shown in Figs.6-7, in an embodiment, the receiving coil assembly 200' comprises a ferrite core 210' and a receiving coil 220' wound on the ferrite core 210'.

Fig.8 shows an illustrative perspective view of the wireless power supply device according to the second exemplary embodiment of the present invention, wherein the ferrite electromagnetic shielding member 400' is received in the metal case 300', the transmitting coil 100' is received in the ferrite electromagnetic shielding member 400', the receiving coil assembly 200' is not inserted into the metal case 300' ; Fig.9 shows an illustrative perspective view of the wireless power supply device of Fig.8.

As shown in Figs.8-9, in an embodiment, the ferrite electromagnetic shielding member 400' is received in the metal case 300' ; the transmitting coil 100' is received in the ferrite electromagnetic shielding member 400' . In this way, the transmitting coil 100' is separated from the metal case 300' by the ferrite electromagnetic shielding member 400'. Thereby, it may reduce the eddy current effect on the metal case 300', and prevent the metal case 300' from overheating, improving the efficiency and the stability of the wireless power supply.

Fig.10 shows an illustrative perspective view of the wireless power supply device according to the second exemplary embodiment of the present invention, wherein the ferrite electromagnetic shielding member 400' is received in the metal case 300', the transmitting coil 100' is received in the ferrite electromagnetic shielding member 400', the receiving coil assembly 200' is inserted into the metal case 300' ; Fig.11 shows an illustrative assembled view of the wireless power supply device of Fig.10.

As shown in Figs.8-11, in an embodiment, a second window 33 corresponding to the first window 43 is formed in the top wall 330' of the metal case 300'. The receiving coil assembly 200' is adapted to be moved into the receiving chamber 401 ' through the first window 43 and the second window 33 and located at a predetermined position in the receiving chamber 401 ', so as to be electromagnetically coupled with the transmitting coil 100' .

Fig.12 shows an illustrative perspective view of the transmitting coil 100' and the receiving coil assembly 200' of the wireless power supply device of Fig.10.

As shown in Figs.10- 12, in an embodiment, when the receiving coil assembly 200' is moved into and located at the predetermined position in the receiving chamber 401 ', a center axis of the transmitting coil 100' is parallel to that of the receiving coil 220' . That is, a winding direction of the transmitting coil 100' is parallel to that of the receiving coil 220'.

As shown in Figs.6, 8-11, in an embodiment, the metal case 300' further comprises a pair of side walls 310', 320' at both sides of the top wall 330' thereof. The inside space 30 is defined by the top wall 330' and the pair of side walls 310', 320' of the metal case 300'. In the illustrated embodiment, the metal case 300' has a cross section substantially exhibiting an inverted-U shape.

As shown in Figs.6, 8-11, in an embodiment, the ferrite electromagnetic shielding member 400' further comprises a pair of side walls 410', 420' at both sides of the top wall 430' thereof. The receiving chamber 40 is defined by the top wall 430' and the pair of side walls 410', 420' of the ferrite electromagnetic shielding member 400' . In the illustrated embodiment, the ferrite electromagnetic shielding member 400' is formed as a case with a substantially inverted-U shaped cross- section.

As shown in Figs.7 and 12, in an embodiment, the ferrite core 210' exhibits a cuboid shape and has a top surface, a bottom surface and a peripheral surface between the top surface and the bottom surface. The receiving coil 220' is wound on the peripheral surface of the ferrite core 210'.

As shown in Figs.7 and 12, in an embodiment, the transmitting coil 100' may be a hollow rectangular coil.

Please be noted that the shape of the transmitting coil 100' and the receiving coil 220' are not limited to the illustrated embodiments, they may have any other suitable shape, as long as the internal magnetic field of the coil is evenly distributed when the coil is energized.

As shown in Figs.6- 12, in an embodiment, a length of the transmitting coil 100' is longer than that of the receiving coil 220', so that a plurality of receiving coils 200' are adapted to be received in different locations in a single transmitting coil 100' in the length direction of the transmitting coil 100' at the same time. Thereby, the plurality of receiving coils 200' may be electromagnetically coupled with the single transmitting coil assembly 100 at the same time.

As shown in Figs.6- 12, in an embodiment, a plurality of first windows 43 are formed in the top wall 430' of the ferrite electromagnetic shielding member 400'. A plurality of second windows 33 corresponding to the plurality of first windows 43 , respectively, are formed in the top wall 330' of the metal case 300'. In this way, the plurality of receiving coil assemblies 200' are adapted to be moved into the receiving chamber 401 ' through the plurality of first windows 43 and the plurality of second windows 33 , so as to be electromagnetically coupled with the single transmitting coil 100' provided in the receiving chamber 401 '.

In an embodiment, the transmitting coil 100' may be connected to a circuit board (not shown). The circuit board may have a DC- AC conversion circuit for converting a direct current into an alternating current. The alternating current from the DC-AC conversion circuit may flow through a matching circuit on the circuit board. Then, it may be used to drive the transmitting coil. The receiving coil assembly 200' may be connected to another circuit board (not shown). In order to drive a load, the other circuit board may have a matching circuit, a rectifier, a filter and a DC-DC conversion circuit.

Although it is not shown, in another embodiment of the present invention, there is also provided an electrical apparatus. The electrical apparatus may comprise a load and the above wireless power supply device configured to supply power to the load.

In an embodiment, the aforementioned electrical apparatus may comprise but not limit to a refrigerator, a washing machine, an air conditioners, etc. It should be appreciated for those skilled in this art that the above embodiments are intended to be illustrated, and not restrictive. For example, many modifications may be made to the above embodiments by those skilled in this art, and various features described in different embodiments may be freely combined with each other without conflicting in configuration or principle.

Although several exemplary embodiments have been shown and described, it would be appreciated by those skilled in the art that various changes or modifications may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

As used herein, an element recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to "one embodiment" of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments "comprising" or "having" an element or a plurality of elements having a particular property may include additional such elements not having that property.