CN1653669A - Contactless power transmission device and method - Google Patents

Abstract

A system and method for transferring electrical energy without the need for direct conductive contact is disclosed. The invention provides a primary unit having a power source and a substantially laminar charging surface. The charging surface has at least one conductive line that generates an electromagnetic field when an electric current flows therethrough and has a charging area defined within the range of the charging surface. The at least one conductor is arranged such that the lines of electromagnetic field generated by the at least one conductor are substantially parallel to the plane of the charging surface or at an angle of at least 45 ° or less to the charging surface within the charging region; the invention also provides at least one secondary device. The secondary device includes at least one wire that may be wound around a magnetic core. Since the electromagnetic field is spread over the charging area and is usually kept parallel or approximately parallel to the charging area, the coupling to a flat secondary device, such as a mobile phone, is greatly improved from different directions.

Description

Contactless power transmission device and method

This application claims priority to UK Patent Application Nos. 0210886.8, 0213024.3, 0225006.6 and 0228425.5 filed on 13 May 2002, 7 June 2002, 28 October 2002 and 6 December 2002 respectively, and Priority to US Patent Application No. 10/326,571, filed December 20, 2002. The entire contents of all of these prior patent applications are incorporated by reference in this application.

technical field

The invention relates to a new device and method for transmitting electrical energy in a contactless manner.

Background technique

Many of today's portable devices incorporate "auxiliary" batteries that can be recharged, saving the user the cost and inconvenience of having to periodically purchase new batteries. Examples of these portable devices include cellular telephones, laptop computers, handheld 500 series personal digital assistants, electric shavers, and electric toothbrushes. In some of these devices, the battery is recharged through inductive coupling rather than a direct electrical connection. Examples of this include Braun Oral B's Plak Control electric toothbrush, Panasonic's digital cordless phone solution KX-PH15AL and Panasonic's ES70/40 series of multi-head men's shavers.

Each such device typically has an adapter or charger that takes power from a mains supply, car cigarette lighter, or other source and converts it into a form suitable for charging a battery. Traditional methods of powering or charging these devices suffer from a number of problems:

・The characteristics of the battery in each device and the method of connecting to the battery vary greatly depending on the manufacturer and the device. So a user who owns several of these devices must also own several different adapters. If users plan to travel and want to use their devices during this time, they will have to bring all their chargers with them.

• These adapters and chargers often require the user to plug a small connector into the device or place the device in a cradle with precise alignment, which is inconvenient. If the user fails to plug or put their device into a charger and the device dies, the device becomes useless and important data stored locally on the device may even be lost.

In addition, most adapters and chargers have to be plugged into an electrical outlet, so if several adapters and chargers are used together, they will take up space on the outlet strip and cause the wires to be messy and messy.

• In addition to the above-mentioned problems with traditional methods of recharging devices, there are many practical problems with devices having open electrical contacts. For example, the device cannot be used in wet environments due to the possibility of corroding or shorting the contacts, and it cannot be used in flammable gas atmospheres due to the possibility of sparking.

Chargers using inductive charging do not need to have open electrical contacts, thus allowing the adapter and device to be sealed and used in wet environments (eg the electric toothbrush mentioned above is designed for use in the bathroom). However, this charger still suffers from all the other problems mentioned above. For example, the device still needs to be placed precisely in the charger so that the device and charger are in predetermined relative positions (see Figures 1a and 1b). Adapters are still only designed for use with a certain make and type of device, and are still only capable of charging one device at a time. As a result, users still need to own and manage multiple different adapters.

There are also universal chargers (such as the Maha MH-C777+ Universal Charger) that allow battery packs of different shapes and characteristics to be removed from a device and charged using the same device. While these universal chargers eliminate the need to have different chargers for different devices, they create an even greater inconvenience for the user because the battery pack first needs to be removed and then the charger needs to be adjusted , and the battery pack needs to be placed precisely in or relative to the charger. Additionally, time must be spent to determine the correct pair of battery pack metal contacts that the charger must use.

It is known from US 3,938,018 "Induction charging system" which provides a contactless battery charging device by means of which, when the device is placed in a recess on the primary side, the The induction coil can be aligned with the horizontal induction coil on the secondary side device. This dimple ensures the more precise alignment necessary for this design, thus ensuring good coupling between the primary and secondary coils.

It is also known from US 5,959,433 "Universal Inductive Battery Charger System" which provides a contactless battery charging system. The described battery charger includes a single charging coil that generates magnetic flux lines that will induce current in a battery pack that may belong to a cell phone or laptop computer.

It is also known from US 4,873,677 "Charging Apparatus for an Electronic Device" which provides a device for charging an electronic device, which includes a pair of coils. The pair of coils are designed to work in anti-phase, so that magnetic field lines are coupled from one coil to the other. An electronic device such as a watch can be placed on these two coils to receive power.

It is also known from US 5,952,814 "Induction charging apparatus and an electronic device" which provides an inductive charger for charging a rechargeable battery. The housing of the electronic device is shaped to match the inner shape of the charger, allowing precise alignment of the primary and secondary coils.

It is also known from US 6,208,115 "Battery substitute pack" which provides an alternative battery pack which can be charged inductively.

It is known from WO 00/61400 "Device for Inductively Transmitting Electrical Power" which provides a method of inductively transferring electrical energy to a transmitting device.

It is known from WO 95/11545 "Inductive power pick-upcoils", which provides a system for inductively supplying electric power to electric vehicles from a series of built-in flat primary coils.

To overcome the limitations of inductive power transfer systems that require axial alignment of the secondary with the primary, an obvious solution might be to use a simple inductive power transfer system by which the primary can be An electromagnetic field is emitted over a larger area (see Figure 2a). The user can simply place one or more devices to be charged within range of the primary device, without requiring their precise placement. For example, this primary device may comprise a coil surrounding a larger area. When current flows through the coil, an electromagnetic field is created that extends over a large area within which the device can be placed anywhere. Although this method works in theory, it has many drawbacks. First, the intensity of the electromagnetic emission is controlled by the adjustment range. This means that the method only supports a limited rate of power transfer. Additionally, many objects can be affected by the presence of strong magnetic fields. For example, data stored on a credit card could be corrupted and eddy currents would be induced inside objects made of metal, with undesired heating effects. Additionally, if secondary devices including conventional coils (see Figure 2a) are placed against a metal enclosure such as a copper plate within a printed circuit board or a battery, the coupling can be significantly reduced.

In order to avoid the generation of large magnetic fields, it may be suggested to use a coil array, by means of which only the required coils are activated (see FIG. 3 ). The method is described in a paper entitled "Coil Shape in Desk-type Contactless Power Station System" published on November 29, 2001 in the Journal of the Japanese Magnetic Society. In one embodiment of the multi-coil principle, the sensor system detects the relative position of the secondary device with respect to the primary device. The control system then activates the corresponding coils to transfer power to the secondary device in a positioned manner. While this approach provides a solution to the problems listed previously, it is complex and expensive to implement. The extent to which the primary field can be positioned is limited by the number of coils and thus the number of drive circuits used (ie the "breakdown" of the primary arrangement). The cost of a multi-coil system would greatly limit the commercial application of this principle. Uneven field distribution is also a defect. When all the coils in the primary device are activated, they are taken together to be equivalent to one large coil, whose magnetic field distribution shows a minimum at the center of the coil.

Another approach is outlined in US 5,519,262 "Near Field Power Coupling System", where the primary device has a large number of narrow induction coils (or optionally capacitive plates) arranged from one end of a flat plate to the other, A large vertical field is generated that is driven in a phase-shifted manner, causing a motion sine wave to move across the plate. The receiving device is arranged with two vertical field receiving devices, so that no matter where the receiving device is located on the board, it can always collect power from at least one receiving device. Although this solution also provides freedom of movement for the device, it has some disadvantages in that it requires a complex secondary arrangement, has a fixed resolution and is poorly coupled since the return flux path is through air.

None of the prior art solutions satisfactorily solves all the problems described. It would be desirable to have a solution that transfers power to portable devices with all of the following characteristics and can be implemented at a cost-effective manner:

Versatility: a single primary unit that can power different secondary units with different power requirements, eliminating the need for multiple different adapters and chargers;

Convenience: a single primary unit that allows the secondary unit to be placed anywhere within effective proximity, eliminating the need for the secondary unit to be plugged into or placed precisely relative to the adapter or charger;

• Multiple Loads: A single primary device that can simultaneously power several different secondary devices with different power requirements.

·Flexibility for use in different environments: a single primary device, which can provide power to the secondary device without requiring direct electrical contact, allowing the secondary device and the primary device itself to be used in wet, gas-containing, clean environments and other abnormal circumstances;

Low electromagnetic emission: A single primary device that transmits electrical energy in a manner that minimizes the strength and size of the generated magnetic field.

In addition, it is understood that portable devices are being produced in large numbers, and all of them require batteries to provide them with power. Primary cells or their battery packs must be disposed of after they are used up, which is expensive and pollutes the environment. The accumulator or accumulator pack can be recharged and reused.

Many portable devices have containers for batteries such as AA, AAA, C, D, and PP3 that meet industry standard sizes and voltages. This enables the user to freely choose whether to use primary or secondary batteries and different types of batteries. Once depleted, the battery usually must be removed from the device and placed in a separate charging unit. Alternatively, some portable devices have built-in charging circuitry that allows the battery to charge in situ while the device is plugged into an external power source.

It is inconvenient for the user to have to remove the battery from the device to charge it or plug the device into an external power source to charge it in situ. It would be nice to have some contactless means of charging the battery without having to do any of the above.

Some portable devices can receive power from a charger by inductive coupling, such as Braun Oral B's Plak Control toothbrush. Such portable devices typically have a custom, dedicated power receiving module built into the device, which is then connected to an internal standard battery or battery pack (which may or may not be removable).

However, it would be convenient if the user could convert any portable device that accepts industry-standard battery sizes into an inductively charged device simply by installing an inductively rechargeable battery or battery pack, in which the Charge an inductively rechargeable cell or battery pack on a remote charger.

Examples of prior art also include US 6,208,115, which discloses an alternative battery pack that can be charged inductively.

Contents of the invention

According to a first aspect of the present invention there is provided a system for transferring electrical energy without requiring direct conductive contact, the system comprising:

i) primary means comprising a substantially laminar charging surface and at least one means for generating an electromagnetic field distributed two-dimensionally in a predetermined area within or parallel to the charging surface so as to define at least one substantially A charging area of a charging surface coextensive with a predetermined area, the charging area having a width and a length on the charging surface, wherein the device is configured in such a way that when a predetermined current is delivered to the device and the primary device is When effectively electromagnetically isolated, the electromagnetic field produced by the device has such electromagnetic field lines that, when averaged over any quarter-length portion of the charging area measured in a direction parallel to the electromagnetic field lines, the electromagnetic field lines at an angle of 45° or less proximate to the charging surface and distributed in two dimensions over the charging surface; and wherein the height of the device, measured substantially perpendicular to the charging area, is less than the width or length of the charging area; as well as

ii) at least one secondary device comprising at least one electrical lead; wherein the electromagnetic field lines are coupled to at least one lead of the at least one secondary device when the at least one primary device is placed on or close to the charging area of the primary device , and induce a current to flow in it.

According to a second aspect of the present invention there is provided a primary device for transferring electrical energy without requiring direct conductive contact, the primary device comprising a substantially lamellar charging surface and at least one means for generating an electromagnetic field, the device two-dimensional distribution within or parallel to a predetermined area of the charging surface to define at least one charging area of the charging surface substantially coextensive with the predetermined area, the charging area having a width and a length on the charging surface, wherein , the device is configured in such a way that when a predetermined current is delivered into the device and the primary device is effectively electromagnetically isolated, the electromagnetic field generated by the device has electromagnetic field lines that are measured in a direction parallel to the field lines Electromagnetic field lines forming an angle of 45° or less close to the charging surface and distributed in two dimensions over the charging surface when averaged over any quarter-length portion of the charging area of the charging area; and Wherein the height of the device measured substantially perpendicular to the charging area is smaller than the width or length of the charging area.

According to a third aspect of the present invention there is provided a method of transferring electrical energy in a non-conductive manner from a primary device comprising a substantially laminar charging surface and at least one means for generating an electromagnetic field, to a secondary device, The device is distributed two-dimensionally within a predetermined area of the charging surface or parallel to the charging surface to define at least one charging area of the charging surface substantially coextensive with the predetermined area, the charging area having a width and a length on the charging surface , the height of the device measured substantially perpendicular to the charging area is less than the width or length of the charging area, and the secondary device has at least one electrical lead; wherein:

i) The electromagnetic field produced when a predetermined current is applied to the device and measured when the primary device is effectively electromagnetically isolated has electromagnetic field lines, any quarter-length portion of the charging area measured in a direction parallel to the field lines When averaging over electromagnetic field lines above, the electromagnetic field lines form an angle of 45° or less close to the charging surface and are distributed in two dimensions over at least one charging area when averaging over the charging areas; and

ii) Electromagnetic fields couple to the leads of the secondary device when they are placed on or close to the charging area.

According to a fourth aspect of the present invention there is provided a secondary device for use with the system, device or method of the first, second or third aspect. The secondary device includes at least one electrical lead and has a substantially sheet-like form factor.

In the context of this application, the word "lamellae" defines a geometric figure in the shape of a sheet or sheet. The flakes or sheets may be substantially flat, or may be curved.

The primary device may comprise at least one power supply for the device for generating an electromagnetic field, or may be provided with a connector or the like enabling connection of the at least one device to an external power source.

In some embodiments, the height of the means for generating the electromagnetic field is no more than (only) half the width or half the length of the charging area; in some embodiments, the height may be only 1/5 of the width of the charging area or 1/5 of the length.

At least one electrical conductor in the secondary arrangement can be wound around a magnetic core for concentrating the incoming flux. In particular, the magnetic core, if provided, provides a path of least resistance to the flux lines of the electromagnetic field generated by the primary device. The magnetic core can be amorphous magnetically permeable material. In some embodiments, an amorphous core need not be used.

If an amorphous magnetic core is provided, the amorphous magnetic material is preferably in the unannealed or substantially cast state. The material may be at least 70% unannealed, or preferably at least 90% unannealed. This is because annealing tends to make amorphous magnetic materials susceptible to shattering, which is disadvantageous for inclusion in devices such as mobile phones, which may, for example, be subject to severe impacts due to accidental drops. In a particularly preferred embodiment, the amorphous magnetic material is in the form of a flexible ribbon, which may comprise one or more layers of one or more of the same or different amorphous magnetic materials. Suitable materials include alloys that may include iron, boron and silicon or other suitable materials. The alloy is melted and then rapidly cooled ("quenched") so that it does not have time to crystallize when it solidifies, leaving the alloy in a glassy, amorphous state. Suitable materials include Metglas ^(R) 2714A and similar materials. Permalloy or permalloy or the like may also be used.

If a magnetic core is provided, the magnetic core in the secondary device is preferably a highly permeable magnetic core. Such cores preferably have a relative permeability of 100, more preferably of at least 500, most preferably of at least 1000, and especially advantageously of the order of at least 10,000 or 100,000.

The at least one means for generating an electromagnetic field may be a coil, eg in the form of a length of wire or a printed strip, or may be in the form of a suitably structured conductive plate, or the means may comprise any suitable arrangement of wires. The preferred material is copper, although other conductive materials, generally metals, may suitably be used. It should be understood that the term "coil" herein is intended to include any suitable electrical conductor forming an electrical circuit through which electrical current can flow to generate an electromagnetic field. In particular, a "coil" need not be wound around a magnetic core or bobbin or the like, but can be a simple or complex loop or equivalent structure.

Preferably, the charging area of the primary device is large enough to accommodate the wires and/or magnetic core of the secondary device in multiple orientations. In a particularly preferred embodiment, the charging area is large enough to accommodate the wires and/or the magnetic core of the secondary device in any orientation. In this way, power transfer from the primary device to the secondary device can be achieved without having to align the leads of the secondary device in any particular direction and/or magnetic core.

The substantially sheet-like charging surface of the primary device may be substantially flat, or may be curved, or designed to fit into a predetermined space, such as a car dashboard glove box or the like. It is especially preferred that the means for generating the electromagnetic field do not protrude from or beyond the charging surface.

An important characteristic of devices for generating electromagnetic fields within primary devices is that the Electromagnetic field lines distributed in two dimensions over at least one of the charged regions at angles of 45° or less close to the charged region (e.g., less than the height or width of the charged region) and generally parallel to the field lines The average is taken over any quarter-length portion of the charging area measured in the direction. Measurements of field lines in this relationship should be understood as measurements of field lines when averaged over a quarter of the length of the charged region, rather than instantaneous point measurements. In some embodiments, the field lines are at an angle of 30° or less. In some embodiments, the field lines are substantially parallel to at least a central portion of the indicated charging region. This is the exact opposite of prior art systems. In prior art systems, the field lines are often substantially perpendicular to one surface of the primary device. By generating an electromagnetic field that is more or less parallel to the charging area or that has at least one effectively resolved component parallel to the charging area, it is possible to control the field to produce angular variations in the plane of the charging area or in a plane parallel to it, such that The angular variation helps to avoid any stationary nulls within the electromagnetic field which would otherwise reduce the charging efficiency for a particular orientation of the secondary device on the charging surface. The direction of the field lines can be rotated in one or both directions through a full or semicircle. Alternatively, the direction of the magnetic field may "jitter" or fluctuate, or may switch between one or more directions. In more complex structures, the direction of the field lines can be varied in Lissajous figures, etc.

In some embodiments, the field lines may be substantially parallel to each other at any particular charge region, or at least have a decomposed component within or in a plane parallel to the charge region that is substantially mutually parallel at any particular moment. parallel.

It should be understood that one means for generating an electromagnetic field can be used to provide an electromagnetic field for more than one charging area; it should also be appreciated that more than one means can be used for providing an electromagnetic field for only one charging area. In other words, there is not necessarily a one-to-one correspondence between the means for generating the electromagnetic field and the charging area.

The secondary device can take a substantially flat form factor with a core thickness of 2 mm or less. Using a material such as one or more amorphous metal plates, it is possible to reduce the core thickness to 1mm or less for applications where size and weight are important. See Figure 7a.

In a preferred embodiment, the primary means may comprise a pair of wires having adjacent coplanar windings, the wires having linear portions arranged substantially parallel to each other for generating a substantially uniform electromagnetic field generally parallel to the plane of the windings. extended, or at an angle of 45° or less to the plane of the winding, but substantially at right angles to the parallel portion.

The winding in this embodiment may be configured in a generally helical shape comprising a series of turns with substantially parallel straight sections.

Advantageously, the primary device may comprise a first pair and a second pair of conductors, the two pairs of conductors being disposed in substantially parallel planes, and the substantially parallel linear portions of the first pair of conductors being generally aligned with the substantially parallel linear portions of the second pair of conductors. The parts are arranged at right angles; the primary device also includes a driver circuit arranged to drive the two pairs of wires in such a way as to generate a resultant field rotating in a plane substantially parallel to the plane of the windings.

According to a fifth aspect of the present invention there is provided a system for transferring electrical energy in a contactless manner, the system comprising:

Primary means consisting of at least one electric coil, each of which is characterized by at least one active area, two or more conductors making it possible for the secondary means to approach a part of this active area placed in such a manner as to be substantially distributed over the area, the net instantaneous current flowing in a particular direction in the active area is substantially non-zero;

At least one secondary device comprising wire wrapped around a high permeability magnetic core in such a way that it is possible to place the secondary device close to the surface of the primary device in an area where the net instantaneous current is substantially not zero;

Thus, when the central axis of the winding is close to the active area of the primary device, is not substantially perpendicular to the plane of the active area of the primary device, and is not substantially parallel to the wires in the active area of at least one coil of the primary device, at least one The secondary device is capable of receiving power through electromagnetic induction.

Where the secondary device contains an inductively rechargeable battery or cell, which may have a major axis and is capable of being charged by an alternating field flowing along the major axis of the battery or cell, comprising:

· Housing and external electrical connections approximately the size of an industry standard battery pack or cell

·Energy storage device

· Optional magnetic field line gathering device

·Power receiving device

• Means for converting received electrical energy into a form suitable for transmission to the outside of the battery through external electrical connection means, or means for charging energy storage means, or means for both functions.

The proposed invention differs substantially from the design of conventional inductive power transfer systems. The difference between the conventional system and the proposed system can best be elucidated by looking at their respective flux patterns. (see Figure 2a and Figure 4)

• Conventional systems: In conventional systems (see Figure 2a), there is usually a planar primary coil that generates a magnetic field whose flux lines exit the coil plane in a perpendicular manner. Secondary devices usually have circular or square coils surrounding some or all of these flux lines.

• Proposed system: In the proposed system, the magnetic field proceeds substantially horizontally along the surface of the coil plane (see Fig. 4) instead of coming directly out of the coil plane as shown in Fig. 2a. Thus, the secondary device can have an extended winding wound around the core. See Figures 7a and 7b. When the secondary device is placed on top of the primary device, the flux lines will be drawn through the magnetic core of the secondary device as it is the path of least reluctance. This enables the secondary device and the primary device to be effectively coupled. The core and windings of the secondary device can be substantially flattened to form a very thin part.

In describing the present invention, specific terminology will be employed for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected, and it should be understood that each specific term includes all technical synonyms that operate in a similar manner to achieve a similar purpose.

It should be understood that the term "charging area" as used in this patent application may refer to the area of at least one means for generating a field, such as one or more wires in the form of a coil, or the area formed jointly by the primary wires, in In this region, the secondary device can effectively couple the magnetic field lines. Some embodiments regarding charging regions are shown as component 740 in Figures 6a-61 and Figure 9c. A characteristic of the "charging area" is that the conductors are distributed over the active area of the primary means so constructed that it is possible for at least one means for generating a field to be actuated to obtain momentary net magnetic field lines flowing in one direction. A primary device may have more than one charging area. One charging area differs from another when the flux lines cannot be effectively coupled by the secondary device in any rotation at the boundary, such as those shown in Figure 7a.

It should be understood that the term "coil" as used in this patent refers to all wire structures that feature a charging region as described above. This includes wire windings or printed traces or planes as shown in Figure 8e. The wires can be made of copper, gold, alloys or any other suitable material.

The application mentions rotation of the secondary device in several places. It should be clarified here that if the secondary device is rotated, the mentioned axis of rotation is perpendicular to the plane of the charging area.

This fundamental change in design overcomes at least one drawback of conventional systems. The benefits of the proposed invention include:

No precise alignment is required: the secondary device can be placed anywhere on the charging area of the primary device;

Coupling Uniformity: In the proposed invention, the coupling between primary and secondary devices is more uniform over the charging area than conventional primary and secondary coils. In conventional large coil systems (see Fig. 2a), the field strength is minimized at the center of the coil in the coil plane (see Fig. 2b). This means that the minimum field strength must be above a certain threshold if enough power is to be effectively transferred at the central location. The maximum field strength would then be significantly higher than the required threshold, which may lead to undesired results.

• Versatility: Multiple different secondary devices, even those with different power requirements, can be placed within the charging area on the charging surface of the primary device to receive power simultaneously.

Improved Coupling Coefficient: Optional high-permeability magnetic material in the secondary device greatly increases the induced magnetic flux by providing a low reluctance path. This can greatly increase electrical energy transfer.

• Ideal form factor for secondary devices: The geometry of the present system allows the use of thin sheets of magnetic material (eg amorphous metal ribbons). This means that the secondary device can have a sheet-like form factor making it suitable for fitting on the rear of mobile phones and other electronic devices. If a magnetic material is used in the center of a conventional coil, it is possible to increase the volume of the secondary device.

Minimal field leakage: when one or more secondary devices are present within the charging area of the primary device, it is possible to use magnetic materials in such a way that more than half of the magnetic circuit is low reluctance material (see Figure 4d) . This means that for a given magneto-motive force (mmf), more flux lines will flow in. Since the induced voltage is proportional to the rate of change of the coupled magnetic flux, this will increase the power transferred to the secondary device. The fewer and shorter air gaps in the magnetic circuit, the fewer the edges of the field and the closer the field lines are to the surface of the primary, so leakage is minimized.

• Cost efficient: Unlike multi-coil designs, the inventive solution requires a simpler control system and fewer components.

· Free pivoting of the secondary device: If the secondary device is laminar or optionally even cylindrical (see Figure 10), it can be constructed in such a way that it remains well coupled to the magnetic field lines regardless of its Whether to rotate around the longest axis. This may be especially an advantage if the secondary device is a battery cell installed in another device, when the pivoting of the secondary device may be difficult to control.

• The magnetic core in the secondary arrangement may be placed in the vicinity of other parallel metal planes in or near the device, eg a copper printed circuit board or an aluminum lid. In this case, the performance of embodiments of the present invention is substantially better than that of conventional core-wound coils, because field lines passing through a conventional device coil would be subject to flux repulsion if the conventional device coil were placed facing a metal plane ( Because the magnetic field lines must propagate perpendicular to the coil plane). Since, in the embodiments of the present invention, the magnetic field lines propagate along the plane of the magnetic core, and therefore also along the plane of the metal, the performance is improved. An added benefit is that the magnetic core within the secondary device of embodiments of the present invention can act as a bridge between the electromagnetic field generated by the primary device and the electromagnetic field generated by any components on the other side of the core, such as circuitry and battery cells. shield.

• Since the magnetic core of the secondary device of the embodiment of the present invention has a higher permeability than air, it serves to concentrate flux lines, which capture more flux lines that would otherwise flow through an equivalent air cross-section. The size of the core "form factor" (equivalent field line capture range) is determined to a first order approximation by the longest planar dimension of the core. Therefore, if the planar dimensions of the magnetic core of the secondary device of an embodiment of the present invention have a large non-square aspect ratio, such as a rectangle with an aspect ratio of 4:1 instead of a square with an aspect ratio of 1:1, It will capture proportionally more of any field lines propagating in a direction parallel to the longest planar dimension. Therefore, if the core is used in a device with restricted planar shape proportions (for example, long and thin devices such as earphones or pens), its performance will be greatly improved compared to that of a conventional coil in the same area.

The primary unit usually consists of the following components. (See Figure 5)

• Power supply: This power supply converts the mains voltage to a lower voltage direct current. This is usually a conventional transformer or switching mode power supply;

• Control means: The control means have the function of maintaining the resonance of the circuit if the inductance of the means used to generate the field varies with the presence of secondary means. To enable this function, the control means may be coupled to sensing means which feed back the current state of the circuit. It can also be coupled with a bank of capacitors that can be switched in or out as required. If the means for generating the field requires more than one drive circuit, the control means can also adjust parameters such as the phase difference or the number of on/off of the different drive circuits to achieve the desired result. It is also possible to design the Q (quality factor) of the system to work within a certain inductance range, so that the above control system is no longer needed;

• Drive circuit: The drive circuit is controlled by the control device and drives a varying current through the device or a part of the device for generating the field. Depending on the number of individual components in the device, there may be more than one drive circuit;

• A device for generating an electromagnetic field: This device generates an electromagnetic field of a predetermined shape and strength using current supplied from a drive circuit. The specific structure of the device defines the shape and strength of the field produced. The device may include a magnetic material acting as a magnetic guide, and also include one or more separate drive components (windings), which together form the charging region. Various embodiment designs are possible, an example of which is shown in FIG. 6 .

• Sensing device: The sensing device retrieves and sends relevant data to the control device for analysis.

The secondary device generally consists of the following components, as shown in FIG. 5 .

• Magnetic device: The magnetic device converts the energy stored in the magnetic field generated by the primary device back into electrical energy. This is usually accomplished by means of windings wound around a high permeability core. The largest dimension of the core usually coincides with the central axis of the winding.

• Conversion means: This conversion means converts the fluctuating current received from the magnetic means into a form useful to the equipment to which it is coupled. For example, the conversion means can convert fluctuating currents into unregulated direct current by means of full-wave bridge rectifiers and filter capacitors. In other cases, the conversion circuit may be coupled to the heating element or battery charger. There is also usually a capacitor connected in parallel or in series with the magnetic device to form a resonant circuit at the operating frequency of the primary device.

In typical operation, one or more secondary devices are placed over the charging surface of the primary device. The magnetic field lines flow through at least one conductor and/or the magnetic core of an existing secondary device and induce a current. Depending on the configuration of the means for generating the field within the primary device, the rotational positioning of the secondary device can affect the number of coupled flux lines.

primary device

Primary devices can exist in many different forms, such as:

A flat platform or pad that can be placed on tables and other smooth surfaces;

Built into furniture such as desks, tables, counters, chairs, bookshelves, etc., making the primary unit invisible;

Parts of containers, such as drawers, boxes, car dashboard cabinets, and containers for power tools;

• A flat platform or pad that can be glued to a wall and used vertically.

The primary unit can be powered from different sources such as:

· AC mains socket

·Vehicle ignition socket

·Battery

·The fuel cell

·solar panel

· Human power

The primary device may be small enough that only one secondary device is housed on the charging surface within a single charging area, or large enough to simultaneously house multiple secondary devices, often housed in different charging areas.

The means for generating the field within the primary means may be driven at the mains frequency (50 Hz or 60 Hz) or some higher frequency.

The sensing means of the primary device can detect the presence of the secondary device, the number of secondary devices present, and even the presence of other magnetic materials that are not part of the secondary device. This sensed information can be used to control the current delivered to the field generating means of the primary means.

The primary device and/or the secondary device may be substantially waterproof or explosion-proof.

The primary device and/or the secondary device may be sealed to a standard such as IP66.

The primary device may include a visual indicator (such as, but not limited to, a light-emitting device such as a light-emitting diode, an electrophosphorescent display, a light-emitting polymer, or a light-reflecting device such as a liquid crystal display or MIT electronic paper) to indicate that the primary device is currently status of the secondary device, the presence of the secondary device, or the number of secondary devices present, or any combination of the above.

Devices for generating electromagnetic fields

Field generating means referred to in this application include wires of all structures, wherein:

The conductors are substantially distributed in a plane and;

• There is a planar substantial area where there is a non-zero net instantaneous current. Given the correct orientation, the secondary device will efficiently couple and receive power over these areas. (see Figure 6)

• The wire is capable of generating an electromagnetic field in which the field lines are at an angle of 45° or less to, or substantially parallel to, a substantial area of the plane.

Figure 6 shows some possible configurations of such primary wires. While most of the structures are actually coil windings, it should be realized that planes of wire not normally considered coils can be achieved to the same effect (see Figure 6e). The drawings are representative examples, but are not exhaustive. These wires or coils can be used in combination to allow effective coupling of the secondary device in all directions while on the charging area of the primary device.

magnetic material

It is possible to use magnetic materials in primary devices to enhance performance.

·Magnetic material can be placed under one or more charging areas or the entire charging surface so that there is also a low reluctance path under the conductor for the flux to complete its path. In theory, a magnetic circuit is similar to an electric circuit. Voltage is analogous to magnetomotive force (mmf), electrical resistance is analogous to reluctance, and current is analogous to magnetic field lines (magnetic flux). From this it can be seen that, for a given mmf, if the reluctance of the path is reduced, the flux flow will increase. By arranging magnetic material underneath the charging area, the reluctance of the magnetic circuit is substantially reduced. This actually increases the magnetic flux coupled by the secondary and ultimately the electrical energy transferred. Figure 4d shows a plate of magnetic material placed under the charging area and the resulting magnetic circuit.

• Magnetic material can also be placed above the charging surface and/or charging area, and below the secondary device, to act as a magnetic guide. This permeance performs two functions: First, the reluctance of the entire magnetic circuit is further reduced allowing more flux to flow. Second, it provides a low reluctance path along the upper surface of the charging area, so flux lines will flow through these guides rather than through air. So, this has the effect of keeping the field close to the charging surface of the primary, rather than being contained in the air. The magnetic material used for the permeance can be chosen strategically or intentionally so that the magnetic cores of the secondary devices (if provided) have different magnetic properties. For example, a material with a lower permeability and a higher saturation magnetism can be chosen. A high saturation magnetism means that the material can carry more flux, and a lower permeability means that when the secondary is nearby, a large number of flux lines will choose to pass through the secondary rather than permeate. (see Figure 8)

• In the construction of the field generating means of some primary devices there may be wires which do not form part of the charging area, eg the component referenced 745 in Figures 6a and 6b. In this case, it may be desirable to use a magnetic material to shield these wires from the effect.

Some examples of materials that may be used include, but are not limited to: amorphous metals (metallic glass alloys such as MetGlas ^™ ), wire mesh made of magnetic materials, steel, ferrite cores, permalloys, and permalloys .

Secondary device

The secondary device can have different shapes and forms. Generally, for better magnetic force coupling, the central axis of the wire (eg, coil winding) should not be substantially perpendicular to the charging area.

• The primary device can have the shape of a flat winding (see Fig. 7a). The inner magnetic core can be constructed from a plate of magnetic material such as amorphous metal. This geometry enables secondary devices to fit into the rear of electronic devices such as mobile phones, personal digital assistants and laptops without adding bulk to the device.

• The secondary device may have the shape of an elongated cylinder. Wire can be wrapped around a long cylindrical core (see Figure 7b).

• The secondary device can be an object surrounded by magnetic material. An example would be a standard size (AA, AAA, C, D) or other size/shape (e.g. application-specific/custom) with e.g. magnetic material wrapped around a cylinder and windings wound around the cylinder rechargeable battery pack batteries.

• The secondary device may be a combination of two or more of the above. The above embodiments can even be combined with conventional coils.

The following non-exhaustive list illustrates some examples of objects that may be coupled to the secondary device to receive electrical power. May not be limited to objects described below:

· Mobile communication equipment, such as radios, mobile phones or walkie-talkies;

· Portable computing devices, such as personal digital assistants or palmtop or laptop computers;

· Portable entertainment devices such as music players, gamepads or toys;

Personal hygiene tools, such as toothbrushes, razors, curlers, curling irons;

Portable imaging devices such as video camcorders or cameras;

Containers for things that may need to be heated, such as coffee mugs, plates, rice cookers, nail polish and cosmetic cases;

·Consumer devices such as flashlights, clocks and fans;

Power tools, such as AC and DC drills and screwdrivers;

· Wireless peripherals, such as wireless computer mice, keyboards, and headsets;

Timing devices such as clocks, watches, stop watches and alarm clocks;

A battery pack for insertion into any of the above devices;

· Standard size battery cells.

In the case of non-intelligent secondary devices such as battery cells, some sophisticated charge control may also be required to meter the inductive power supplied to the battery and to handle the situation where multiple batteries in the device have different states of charge. Also, being able to display the "charged" condition becomes especially important for primary devices, since the battery or battery pack may not be easily visible when it is located within other electronic equipment.

Figure 10 shows a possible system comprising an inductively rechargeable battery or battery and a primary device. In addition to freely placing the battery 920 on the (X, Y) plane and arbitrarily rotating around the rZ axis relative to the primary device 910, the battery pack can also be rotated along its rA axis to continuously receive power.

When a user inserts a battery into a portable device, it is not easy to ensure it has any particular pivot. Embodiments of the present invention are therefore highly advantageous in that they ensure that the battery pack is able to receive power when it is rotated in any orientation about rA.

A battery pack or cell may include flux concentrators arranged in a variety of ways:

1. As shown in FIG. 11a, the battery 930 may be wrapped in a cylindrical magnetic flux concentrator 931 around which a wire coil 932 is wound.

a. The cylindrical device can be longer or shorter relative to the length of the battery.

2. As shown in FIG. 11b, the surface of the battery 930 may have a part of a magnetic flux concentrating device 931, and a wire coil 932 is wound on the part of the magnetic flux concentrating device.

a. The portion can conform to the surface of the battery, or be embedded in the battery.

b. The area of the portion can be large or small relative to the periphery of the battery, and the portion can be long or short relative to the length of the battery.

3. As shown in FIG. 11c, the interior of the battery 930 may include a part of a magnetic flux concentrating device 931 on which a wire coil 932 is wound.

a. The portion may be substantially flat, cylindrical, rod-shaped, or any other shape.

b. The width of this part can be larger or smaller relative to the diameter of the battery.

c. The length of this part can be larger or smaller than the length of the battery.

In either of these cases, the flux concentrating means may be a functional part of the battery casing (eg, the outer zinc electrode) or the battery itself (eg, the inner electrode).

Problems involving the charging of accumulators, such as AA rechargeable batteries within equipment, include:

• The terminal voltage may be higher than normal.

• Cells in series may behave abnormally, especially if some cells are charged while others are not.

• Enough power has to be supplied to run the device and charge the battery.

·Battery may be destroyed if fast charging is not performed correctly.

Therefore, it is advantageous to provide some complex charging control means to measure the induced power supplied to the equipment and the battery. Also, being able to display the "charged" status is especially important for primary devices since the battery or battery pack may not be easily visible when it is located within the electronic device.

A cell or battery implemented in this manner may be recharged when installed in another device by placing the device on the primary unit, or by placing the battery Or the battery pack is placed directly on the primary unit for charging.

Multiple battery packs implemented in this manner can be arranged in battery packs as is typical in devices (eg end-to-end or side-by-side), such that a single battery pack can replace a set of batteries.

Alternatively, the secondary device may consist of a flat "adapter" that fits over the battery pack within the device, with thin electrodes acting down between the battery poles and the device contacts.

rotating electromagnetic field

In coils such as those in Figures 6, 9a and 9b, the secondary device can generally only be effectively coupled if the windings are placed substantially parallel to the direction of net current flow in the primary wire as indicated by arrow 1 . In some applications, a primary may be required that will efficiently transfer power to the secondary regardless of the rotation of the secondary, provided that:

the central axis of the secondary conductor is not perpendicular to the plane, and;

• The secondary unit is in close proximity to the primary unit.

To make this feasible, it is possible to have two coils, for example one placed on top of the other, or one coil woven into or with the other coil, the second coil being able to At any point within the active area of the device a net current flow is produced substantially perpendicular to the direction of the first coil. The two coils can be driven alternately such that each is activated for a period of time. Another possibility is to drive two coils a quarter of a period apart, creating a rotating magnetic dipole in the plane. This is shown in FIG. 9 . This is also possible for other combined coil structures.

resonant circuit

Driving coils using parallel or series resonant circuits is well known in the art. For example in a series resonant circuit, the impedance of the coil and capacitor are equal and opposite at resonance, so the total impedance of the circuit is minimum and the current flowing through the primary coil is maximum. The secondary is also typically tuned to the operating frequency to maximize the induced voltage or current.

In some systems like electric toothbrushes it is common to have a circuit that is detuned when the secondary is not present and tuned when the secondary is in place. The presence of magnetic material in the secondary device changes the self-inductance of the primary device and causes the circuit to resonate. In other systems such as passive radiotags, there is no magnetic material in the secondary device, so it does not affect the resonant frequency of the system. These tags are usually small and used remotely from the primary device so that the primary device's induction does not change significantly even in the presence of magnetic material.

In the proposed system, however, this is not the case:

High magnetic permeability magnetic material can be present in the secondary device and used in close proximity to the primary device;

• One or more secondary devices may be immediately adjacent to the primary device at the same time.

This has the effect of significantly changing the induction of the primary device and varying levels depending on the number of secondary devices present on the backing plate. As the inductance of the primary device is changed, the capacitance required for the circuit to resonate at a particular frequency also changes. There are three ways to keep a circuit in resonance:

Dynamically change the working frequency by means of the control system;

Dynamically change the capacitance by means of the control system so that resonance occurs at a predetermined frequency;

• With the help of a low-Q system, the system remains resonant in the inductance range.

The problem with changing the operating frequency is that the secondary device is usually constructed to resonate at a predetermined frequency. If the operating frequency is changed, the secondary device will be detuned. To overcome this problem, the capacitance can be changed without changing the operating frequency. The secondary device can be designed such that each additional device placed close to the primary device will cause the inductance to be of the order of a quantum, while an appropriate capacitor is connected to cause the circuit to resonate at a predetermined frequency. Due to this change in resonant frequency, the number of devices on the charging surface can be detected and the primary device can also sense when something is approaching or moving away from the charging surface. If, in addition to a secondary slave, a magnetically permeable object is placed near the charging surface, it is unlikely to change the system to the intended quantum level. In this case, the system automatically detunes and reduces the current flowing into the coil.

Description of drawings

For a better understanding of the invention, and to show how it may be practiced, reference will now be made, by way of example only, to the accompanying drawings, in which:

Figure 1 shows the magnetic design of a typical prior art contactless power transfer system that requires precise alignment of primary and secondary devices;

Figure 2a shows the magnetic design of another typical prior art contactless power transfer system comprising a large coil in the primary device;

Figure 2b shows the inhomogeneous field distribution inside a large coil at 5 mm from the coil plane, with a minimum in the center;

Figure 3 shows a multi-coil system in which each coil is driven independently to generate a localized field;

Figure 4a shows an embodiment of the proposed system, which shows a substantial difference from the prior art, in that the secondary devices are not included in the figure;

Figure 4b shows an embodiment of the proposed system with two secondary devices;

Figure 4c shows the cross-section of the active area of the primary device, and the equipotential lines of the magnetic flux density generated by the wire;

Figure 4d shows the magnetic circuit of this particular embodiment of the proposed invention;

Figure 5 shows a schematic diagram of an embodiment of a primary device and a secondary device;

Figures 6a to 6l illustrate the design of some alternative embodiments of the field generating means or components of the field generating means of the primary device;

Figures 7a and 7b show some possible designs of the magnetic means of the secondary means;

Figure 8 shows the effect of the flux guide (thickness of the flux guide is exaggerated for clarity);

Figure 8a shows that without permeance, the field tends to spread into the air directly above the active region;

Figure 8b shows the direction of current flow within the wire in this particular embodiment;

Figure 8c shows that when the magnetic material is placed on top of the charging area, the magnetic flux is contained in the magnetic guide;

Figure 8d shows the secondary device on top of the primary device;

Figure 8e shows a cross-section of a primary device without any secondary device;

Figure 8f shows a cross-section of a primary device with a secondary device on top and shows the effect of using a core with a higher permeability than the secondary device;

Figure 9a shows a particular coil arrangement with a net instantaneous current indicated by the direction of the arrow;

Figure 9b shows a coil arrangement similar to Figure 9a except rotated by 90 degrees;

Fig. 9c shows the charging area of the primary device when the coil of Fig. 9a is placed on top of Fig. 9b. This figure shows the effect of a rotating magnetic dipole if the coil in Figure 9a is driven a quarter of a period apart from the coil in Figure 9b;

Figure 10 shows the case where the secondary device has a degree of rotation around the axis;

Figure 11 shows a different arrangement of secondary devices with degrees of rotation around the axis;

Figures 12a and 12b show another embodiment of a coil arrangement of the type shown in Figures 9a and 9b; and

FIG. 13 shows a simple embodiment of the drive electronics.

Detailed ways

Referring first to Figure 1, two examples of prior art contactless power transfer systems are shown, both of which require precise alignment of the primary and secondary devices. This embodiment is typically used for electric toothbrushes or chargers for mobile phones.

FIG. 1 a shows a primary magnetic device 100 and a secondary magnetic device 200 . On the primary magnetic device side, a coil 110 is wound on a magnetic core 120 such as ferrite. Likewise, the secondary side is constituted by a coil 210 wound around another magnetic core 220 . In operation, an alternating current flows into the primary coil 110 and generates magnetic field lines (flux, also called magnetic flux) 1 . When the secondary magnetic device 200 is placed such that it is axially aligned with the primary magnetic device 100 , flux lines 1 will couple from the primary magnetic device into the secondary magnetic device, inducing a voltage across the secondary coil 210 .

Figure 1b shows a split transformer. The primary magnetic device 300 is constituted by a U-shaped magnetic core 320 around which a coil 310 is wound. When an alternating current flows into the primary coil 310, a changing magnetic field line 1 is generated. The secondary magnetic device 400 consists of a second U-shaped magnetic core 420 around which another coil 410 is wound. When the secondary magnetic device 400 is placed on the primary magnetic device 300 so that the arms of the two U-shaped magnetic cores are aligned, the magnetic field lines will be effectively coupled into the secondary U-shaped magnetic core 420 and on the secondary coil 410. A voltage is induced.

Figure 2a is another embodiment of a prior art inductive system commonly used to power radio frequency passive tags. The primary device usually consists of a coil 510 covering a larger area. When multiple secondary devices 520 are located in the area surrounded by the primary coil 510, induced voltages will be generated in these devices. The system does not require precise alignment of the secondary coil 520 with the primary coil 510 . Fig. 2b shows a diagram of the magnitude of the magnetic flux intensity over the area surrounded by the primary coil 510 at 5 mm above the primary coil plane. It shows a non-uniform field with a minimum 530 in the center of the primary coil 510 .

Figure 3 is another embodiment of a prior art induction system in which a multi-coil array is used. The primary magnetic device 600 is composed of a coil array including coils 611 , 612 , and 613 . The secondary magnetic device 700 may consist of a coil 710 . When the secondary magnetic device 700 is close to certain coils of the primary magnetic device 600, the coils 611 and 612 are activated while other coils such as 613 are inactive. The activated coils 611 and 612 generate flux lines, some of which will couple into the secondary magnetic device 700 .

Figure 4 shows an embodiment of the proposed invention. FIG. 4 a shows the primary coil 710 wound or printed in such a way that there is a net instantaneous current in the active area 740 . For example, if a direct current flows through the primary coil 710, the wires within the active area 740 will all have current flowing in the same direction. The current flowing through the primary coil 710 generates the magnetic flux 1 . A layer of magnetic material 730 exists below the charging region to provide a return path for the flux lines. FIG. 4 b shows the same primary magnetic arrangement shown in FIG. 4 a with two secondary arrangements 800 . When the secondary device 800 is placed on the charging area 740 of the primary magnetic device facing the correct orientation, the flux 1 will flow through the magnetic core of the secondary device 800 instead of air. Therefore, the flux 1 flowing through the secondary core will induce a current in the secondary coil.

Figure 4c shows some equipotential lines of the flux density of the magnetic field generated by the wire 711 within the charging region 740 of the primary magnetic arrangement. There is a layer of magnetic material 730 under the wires to provide a low reluctance return path for the flux lines.

Figure 4d shows a cross-section of the charging region 740 of the primary magnetic device. One possible path of the magnetic circuit is shown. The magnetic material 730 provides a low reluctance path to the circuit, and the magnetic core 820 of the secondary magnetic device 800 also provides a low reluctance path. This greatly reduces the distance the flux lines must travel through the air, thus minimizing leakage.

Figure 5 shows a schematic diagram of an embodiment of the overall system of the proposed invention. In this embodiment, the primary device consists of a power supply 760 , a control device 770 , a sensing device 780 and an electromagnetic device 700 . Power supply 760 converts the mains voltage (or other power source) to DC at a voltage suitable for the system. The control device 770 controls a drive device 790 that drives the magnetic device 700 . In this embodiment, the magnetic arrangement consists of two separate drive components coil 1 and coil 2 . Coil 1 and coil 2 are arranged such that the conductors in the charging area of coil 1 are perpendicular to the conductors in the charging area of coil 2 . When the primary unit is activated, the control unit causes a phase shift of 90 degrees between the alternating currents flowing through coil 1 and coil 2 . This creates a rotating magnetic dipole on the surface of the primary magnetic device 700, enabling the secondary device to receive power regardless of the direction of rotation (see Figure 9). In the standby mode where no secondary device is present, the primary device is detuned and the current flow into the magnetic device 700 is minimized. When the secondary device is placed on top of the charging area of the primary device, the inductance of the primary magnetic device 700 changes. This causes the primary circuit to resonate and the current becomes maximum. When there are two secondary devices on the primary device, the inductance is changed to another level and the primary circuit is detuned again. At this point, the control device 770 uses feedback from the sensing device 780 to switch another capacitor into the circuit so that the circuit is tuned again and the current becomes maximum. In this embodiment, the secondary unit is of standard size and up to six standard size devices can simultaneously receive power from the primary unit. Due to the standard size of the secondary devices, changes in inductance due to variations in adjacent secondary devices are quantized to a number of predetermined levels, so that only up to six capacitors are required to keep the system in resonant operation.

Figures 6a to 61 show a number of different embodiments of coil components of a primary magnetic arrangement. These embodiments may be implemented as only the coil components of the primary magnetic device, in which case the rotation of the secondary device is essential for electrical energy transfer. These embodiments can also be implemented in combination, and embodiments not shown here are not excluded. For example, the two coils shown in Figure 6a can be placed at 90 degrees to each other to form a single magnetic device. In Figures 6a-6e, the charging region 740 is formed by a series of wires with net current flow generally in the same direction. In some configurations, such as Fig. 6c, there is no substantial coupling when the secondary is placed directly in the center of the coil, and thus no power transfer. In FIG. 6d there is also no substantial coupling when the secondary device is located in the gap between the two charging regions 740 . FIG. 6 f shows a special coil configuration of the primary device, which is adapted to generate electromagnetic field lines in the charging region 740 substantially parallel to the surface of the primary device. Two primary windings 710 located on either side of the charging area 740 are formed around opposite arms of a generally rectangular flux guide 750 made of magnetic material, the primary windings 710 generating opposing electromagnetic fields. The flux guide 750 contains an electromagnetic field and generates a magnetic dipole in the charge region 740 in the direction of the arrow shown in the figure. When the secondary device is placed in the charging area 740 in a predetermined orientation, a low reluctance path is created and magnetic field lines flow through the secondary device, resulting in efficient coupling and power transfer. It should be appreciated that the flux guide 750 need not be continuous, but could actually be formed as two opposing non-connected horseshoe members.

FIG. 6g shows another possible coil configuration of the primary device adapted to generate electromagnetic field lines within the charging region 740 substantially parallel to the charging surface of the primary device. The primary winding 710 is wound on a magnetic core 750 which may be ferrite or some other suitable material. Charging region 740 comprises a series of wires with net current flowing generally in the same direction. The coil structure of Fig. 6g can actually support or define charging areas 740 both above and below that shown in the figure, and, depending on the design of the primary device, one or both of the charging areas can be used by the secondary device.

Figure 6h shows a variant of the structure of Figure 6g. Unlike the primary windings 710 which are evenly spaced as in Figure 6g, the windings 710 are not evenly spaced. The spacing and variation shown in this figure may be selected or designed to improve performance equalization or field strength level equalization across the charging area 740 .

Figure 6i shows such an embodiment where the two primary windings 710 shown in Figure 6g are in a mutually orthogonal configuration such that the direction of the field lines can be dynamically switched or rotated to other orientations about the plane of the charging surface.

Figures 6j and 6k show an additional double coil configuration of the primary device, which is not a simple geometry with substantially parallel wires.

In FIG. 6j , line 710 represents one of a set of current carrying wires placed in the plane of charging surface 600 . The main wire 710 has any shape, not necessarily several regular figures. In fact, the wire (conductor, also known as conductor) 710 may have a straight part and a curved part, and may cross itself. One or more auxiliary wires 719 are arranged alongside and generally parallel to (at any particular local point) the main wire 710 , only two auxiliary wires 719 are shown here for clarity. The current in the auxiliary wire 719 has the same direction as the current in the main wire 710 . The accessory wires 719 can be connected in series or in parallel to form a single coil arrangement.

In FIG. 6k a set of current carrying wires 720 (only two of which are shown here for clarity) are arranged in the plane of the charging surface 600 . The arrangement of the main conductors 710 is as in FIG. 6j , with each conductor 720 being arranged so as to be locally orthogonal to the main conductor 710 . The wires 720 can be connected in series or in parallel to form a single coil arrangement. If a first sinusoidal current is passed into wire 710, and a second sinusoidal current, 90 degrees phase shifted with respect to the first, is passed into coil 720, then, by changing the relative proportions and signs of the two currents, charging will be seen The direction of the electromagnetic field vector generated at most points on region 740 will be rotated 360 degrees.

Fig. 61 shows another alternative arrangement in which the magnetic core 750 is in the shape of a disc with a hole through the center. A first set of current carrying wires 710 is arranged on the surface of the disk in a helical shape. The second set of wires 720 passes through the center of the disk in a helical form and winds radially towards the periphery. These wires can be driven in such a way, for example with quadrature sinusoidal currents, that when the secondary device is placed at any point in the charging area 740 and rotated about an axis perpendicular to the charging area, the secondary device will not Zero voltage detected.

Figures 7a and 7b are embodiments of the proposed secondary device. The winding 810 is wound on the magnetic core 820 . The two secondary devices may be combined into a single secondary device, eg at right angles, such that the secondary device is effectively coupled to the primary device in all rotations. These secondary devices can also be combined with standard coils such as coil 520 shown in Figure 2a to eliminate dead zones.

Figure 8 shows the effect of the magnetic guide 750 on top of the charging area. The thickness of this material is exaggerated for clarity, but in reality it is on the order of millimeter thickness. The flux guide 750 will minimize leakage and contain the flux lines by reducing the number of flux lines that couple to the secondary device. In Fig. 8a, the primary magnetic arrangement without the magnetic guide 750 is shown. The field will spread into the air directly above the charging area. As shown in Figures 8b to 8f, due to the flux guide 750, the flux lines are contained in the plane of the material and leakage is minimized. In FIG. 8e , the flux lines remain within the magnetic conductor 750 when there is no secondary device 800 at the top. In Fig. 8f, when there is a secondary device 800 with a magnetic core of a material with higher magnetic permeability, part of the flux will flow through the secondary device. The magnetic permeability of the magnetic guide 750 may be chosen such that it has a higher magnetic permeability than typical metals such as steel. When other material such as steel is placed on top, which is not part of the secondary, most of the flux lines will remain within the flux guide 750 rather than passing through the object. The flux guide 750 may not be a continuous layer of magnetic material, but may have a small air gap between them to encourage more flux flow into the secondary device 800 (if the secondary device 800 is present).

Figure 9 shows an embodiment of a primary device using more than one coil. FIG. 9 a shows the coil 710 and the charging area 740 , the current flows in a direction parallel to the arrow 2 . Figure 9b shows a similar coil arranged at 90 degrees to the coil in Figure 9a. When the two coils are placed on top of each other so that the charging area 740 overlaps, the charging area will be as shown in Figure 9c. Such an embodiment would allow the secondary device to be freely rotated and coupled efficiently on top of the primary device.

Figure 10 shows an embodiment in which the secondary device has a degree of pivoting, wherein the secondary device is a battery cell, or has a battery cell embedded therein. In this embodiment, the secondary device can be constructed such that it couples to the primary flux during any axial rotation (rA) relative to the primary device (910), with the same degrees of freedom as described above (i.e., Translation in the (X, Y) plane and rotation about (rZ) arbitrarily perpendicular to the plane of the primary device).

Figure 11a shows an arrangement in which a rechargeable battery cell 930 is surrounded by an optional cylindrical flux concentrator 931 with copper wire 932 wrapped around it. The cylindrical device can be longer or shorter relative to the length of the battery.

Figure 11b shows another arrangement in which the flux concentrator 931 covers only a portion of the battery 930 and is wrapped with copper wire 932 (but not the battery is wrapped with copper wire). The device and copper wire may conform to the surface of the battery. Their area can be large or small relative to the periphery of the battery, and their length can be long or short relative to the length of the battery.

FIG. 11c shows another arrangement in which a flux concentrator 931 is embedded within a battery 930 and is wound with a copper wire 932 . The device can be substantially flat, cylindrical, rod-shaped, or any other shape with a width that can be greater or lesser than the diameter of the battery and a length that can be more or less relative to the length of the battery.

In any of the cases shown in Figures 10 and 11, these flux concentrators may also be a functional part of the battery pack casing (e.g., the outer zinc electrodes), or a functional part of the battery pack itself (e.g., the inner electrodes) .

In either case shown in FIGS. 10 and 11 , electrical energy may be stored in smaller standard batteries (eg, size AAA) mounted within larger standard battery housings (eg, AA).

FIG. 12 shows an embodiment of a primary device similar to that shown in FIG. 9 . Figure 12a shows a coil generating a field horizontal to the page direction. Figure 12b shows another coil generating a field perpendicular to the page, these two coils are arranged in a substantially coplanar manner, possibly one above the other, or even wound around each other in some way. The wires connected to each coil are shown at 940 and the charging area is indicated by arrows 941 .

Figure 13 shows a simple embodiment of the drive means (790 of Figure 5). In this embodiment there is no control device. PIC processor 960 generates two 23.8 kHz square waves 90 degrees out of phase. These square waves are amplified by part 961 and driven into two coil parts 962 which are the same as the magnetic arrangement shown in Figures 12a and 12b. While the drive unit is used to provide a square wave, the high resonant "Q" of the magnetic unit converts the square wave into a sinusoidal waveform.

Preferred features of the invention apply to all aspects of the invention and can be used in any possible combination.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of the claims of the present invention.

Claims (76)

1. One kind do not need direct electric connection just touch can electric energy transmitting system, described system comprises:

   I) primary device, comprise and be roughly laminar charging surface and at least one device that is used to generate an electromagnetic field, the described device that is used to generate an electromagnetic field is in described charging surface or be parallel on the presumptive area of described charging surface and carry out Two dimensional Distribution, with limit at least one roughly with the charging zone of the common described charging surface that extends of described presumptive area, described charging zone has certain width and certain-length on described charging surface, wherein, the described device that is used to generate an electromagnetic field disposes by this way: when scheduled current being supplied with the described device that is used to generate an electromagnetic field, and described primary device is during by effective electromagnetic isolation, the electromagnetic field that is produced by the described device that is used to generate an electromagnetic field has electromagnetic field lines, when when regional any 1/4th length part of the described charging of an orientation measurement that is parallel to described electromagnetic field lines is averaged described electromagnetic field lines, described electromagnetic field lines is near the angle at 45 with it, place or the littler angle of described charging surface, and on described charging surface with Two dimensional Distribution; And wherein, the described device that is used to generate an electromagnetic field is substantially perpendicular to the measured height in described charging zone less than regional width or the length of described charging; And

   Ii) at least one second unit comprises at least one electric conductor;

   Wherein, when described at least one second unit is placed on the charging zone of described primary device or near it the time, at least one electric conductor coupling of described electromagnetic field lines and described at least one second unit, and produce induced current, described induced current flows therein.
2. 2. system according to claim 1, wherein, the described device that is used to generate an electromagnetic field comprises that at least one is in described charging surface or be basically parallel to the electric conductor that described charging surface carries out Two dimensional Distribution.
3. 3. system according to claim 1, wherein, the described device that is used to generate an electromagnetic field comprises that at least one is wound into the electric conductor to the small part of magnetic conduction bobbin, and described magnetic conduction bobbin is in described charging surface or be basically parallel to described charging surface and carry out Two dimensional Distribution.
4. 4. according to the described system of above-mentioned arbitrary claim, wherein, the described device that is used to generate an electromagnetic field comprises a plurality of conductors, and the durection component that described a plurality of conductors are used to described electromagnetic field lines is decomposed on the described charging zone changes in time.
5. 5. system according to claim 4, wherein, the durection component that described a plurality of conductors are used to described electromagnetic field lines is decomposed is changed between at least two different directions.
6. 6. system according to claim 4, wherein, described a plurality of conductors are used to make the durection component of the electromagnetic field lines of being decomposed to move certain angle.
7. 7. system according to claim 6, wherein, described a plurality of conductors are used to make the durection component of the electromagnetic field lines of being decomposed to be rotated.
8. 8. according to the described system of above-mentioned arbitrary claim, wherein, when the electromagnetic field lines on the given charging zone projected on the described charging zone, the electromagnetic field lines on the given charging zone was parallel to each other basically.
9. 9. according to the described system of above-mentioned arbitrary claim, wherein, one the moment net current that described at least one device that is used for generating an electromagnetic field is given when energising flows towards a direction basically.
10. 10. according to the described system of above-mentioned arbitrary claim, wherein, the described device that is used to generate an electromagnetic field does not reach outside the described charging surface.
11. 11. according to the described system of above-mentioned arbitrary claim, wherein, described at least one charging zone is provided with the magnetic material substrate.
12. 12. according to the described system of above-mentioned arbitrary claim, wherein, described primary device comprises the capacitor of at least one alternative work, and described capacitor is used to make the electric capacity of the circuit that comprises described at least one device that is used to generate an electromagnetic field and described at least one capacitor to change in response to the existence that detects one or more second units.
13. 13. according to the described system of above-mentioned arbitrary claim, wherein, described at least one charging zone is provided with magnetic conductance, the relative permeability of described magnetic conductance is lower than the magnetic permeability of the magnetic core of described at least one second unit.
14. 14. according to the described system of above-mentioned arbitrary claim, wherein, described primary device comprises power supply.
15. 15. according to the described system of above-mentioned arbitrary claim, wherein, at least one conductor in the described second unit is around being used for flux magnetic core winding wherein.
16. 16. system according to claim 15, wherein, described magnetic core is a kind of permeability magnetic material.
17. 17. system according to claim 16, wherein, described magnetic core is a kind of amorphous magnetic material.
18. 18. system according to claim 17, wherein, described magnetic core is a kind of amorphous magnetic material of non-annealing basically.
19. 19. according to arbitrary described system in the claim 15 to 18, wherein, described magnetic core forms flexible band.
20. 20. according to the described system of above-mentioned arbitrary claim, wherein, described second unit comprises inductive charging battery pack or battery.
21. 21. system according to claim 20, wherein, described inductive charging battery pack or battery comprise that at least one centers on flux device wound conductor.
22. 22. according to the described system of above-mentioned arbitrary claim, wherein, at least one of described at least one device that is used for generating an electromagnetic field is used for generating an electromagnetic field on more than one charging zone.
23. 23. according to arbitrary described system in the claim 1 to 21, wherein, a plurality of devices that are used to generate an electromagnetic field are used for generating an electromagnetic field on single charging zone.
24. 24. according to the described system of above-mentioned arbitrary claim, wherein, the described height of devices that is used to generate an electromagnetic field is no more than half of the regional length of described charging or half of width.
25. 25. according to the described system of above-mentioned arbitrary claim, wherein, the described height of devices that is used to generate an electromagnetic field be no more than described charging zone length 1/5th or width 1/5th.
26. 26. one kind do not need direct electric connection just touch can electric energy transmitting primary device, described primary device comprises and is roughly laminar charging surface and at least one device that is used to generate an electromagnetic field, the described device that is used to generate an electromagnetic field is in described charging surface or be parallel to Two dimensional Distribution on the presumptive area of described charging surface, with limit at least one roughly with the charging zone of the common described charging surface that extends of described presumptive area, described charging zone has certain width and certain-length on described charging surface, wherein, the described device that is used to generate an electromagnetic field disposes by this way: when scheduled current being supplied with the described device that is used to generate an electromagnetic field, and described primary device is during by effective electromagnetic isolation, the electromagnetic field that is produced by the described device that is used to generate an electromagnetic field has electromagnetic field lines, when when regional any 1/4th length part of the described charging of an orientation measurement that is parallel to described electromagnetic field lines is averaged described electromagnetic field lines, described electromagnetic field lines is near the angle at 45 with it, place or the littler angle of described charging surface, and on described charging surface with Two dimensional Distribution; And wherein, the described device that is used to generate an electromagnetic field is basically perpendicular to the measured height in described charging zone less than regional width or the length of described charging.
27. 27. primary device according to claim 26, wherein, the described device that is used to generate an electromagnetic field comprises that at least one is in described charging surface or be basically parallel to the electric conductor that described charging surface carries out Two dimensional Distribution.
28. 28. primary device according to claim 26, wherein, the described device that is used to generate an electromagnetic field comprises that at least one is wound into the electric conductor to the small part of magnetic conduction bobbin, and described bobbin is in described charging surface or be basically parallel to described charging surface and carry out Two dimensional Distribution.
29. 29. according to arbitrary described primary device in the claim 26 to 28, wherein, the described device that is used to generate an electromagnetic field comprises a plurality of conductors, the durection component that is used to described electromagnetic field lines is decomposed on the described charging zone changes in time.
30. 30. primary device according to claim 29, wherein, described a plurality of conductors are used to make the durection component of the electromagnetic field lines of being decomposed to change between at least two different directions.
31. 31. primary device according to claim 29, wherein, described a plurality of conductors are used to make the durection component of the electromagnetic field lines of being decomposed to move certain angle.
32. 32. primary device according to claim 31, wherein, described a plurality of conductors are used to make the durection component of the electromagnetic field lines of being decomposed to be rotated.
33. 33. according to arbitrary described primary device in the claim 26 to 32, wherein, when the electromagnetic field lines on the given charging zone projected on the described charging zone, the electromagnetic field lines on the described given charging zone was parallel to each other basically.
34. 34. according to arbitrary described primary device in the claim 26 to 33, wherein, one the moment net current that described at least one device that is used for generating an electromagnetic field is given when energising flows towards a direction basically.
35. 35. according to arbitrary described primary device in the claim 26 to 34, wherein, the described device that is used to generate an electromagnetic field does not reach outside the described charging surface.
36. 36. according to arbitrary described primary device in the claim 26 to 35, wherein, described at least one charging zone is provided with the magnetic material substrate.
37. 37. according to arbitrary described primary device in the claim 26 to 36, comprise the capacitor of at least one alternative work, described capacitor is used to make the electric capacity of the circuit that comprises described at least one device that is used to generate an electromagnetic field and described at least one capacitor to change in response to the existence that detects one or more second units.
38. 38. according to arbitrary described primary device in the claim 26 to 37, wherein, described primary device comprises power supply.
39. 39. according to arbitrary described primary device in the claim 26 to 38, wherein, described at least one charging zone is provided with magnetic conductance, the relative permeability of described magnetic conductance is lower than the magnetic permeability that can be arranged on any magnetic core in described at least one second unit.
40. 40. according to arbitrary described primary device in the claim 26 to 39, wherein, at least one of described at least one device that is used for generating an electromagnetic field is used for generating an electromagnetic field on more than one charging zone.
41. 41. according to arbitrary described primary device in the claim 26 to 39, wherein, a plurality of devices that are used to generate an electromagnetic field are used for generating an electromagnetic field on single charging zone.
42. 42. according to arbitrary described primary device in the claim 26 to 41, wherein, the described height of devices that is used to generate an electromagnetic field is no more than half of the regional length of described charging or half of width.
43. 43. according to arbitrary described primary device in the claim 26 to 42, wherein, the described height of devices that is used to generate an electromagnetic field be no more than described charging zone length 1/5th or width 1/5th.
44. 44. method from primary device to second unit that transmit electric energy in non-conductive mode from, described primary device comprises and is roughly laminar charging surface and at least one device that is used to generate an electromagnetic field, the described device that is used to generate an electromagnetic field is in described charging surface or be parallel to Two dimensional Distribution on the presumptive area of described charging surface, with limit at least one roughly with the charging zone of the common described charging surface that extends of described presumptive area, described charging zone has certain width and certain-length on described charging surface, the described device that is used to generate an electromagnetic field is along being basically perpendicular to width or the length of the measured height in described charging zone less than described charging zone, and described second unit has at least one electric conductor; Wherein:

    I) has electromagnetic field lines when the described device that is used to generate an electromagnetic field being passed to scheduled current produces and carrying out measured electromagnetic field during by effective electromagnetic isolation when described primary device, when any 1/4th length in the described charging zone of an orientation measurement that is parallel to described electromagnetic field lines partly go up described electromagnetic field lines are averaged, described electromagnetic field lines is near the angle at 45 with it, place or the littler angle of described charging surface, and when on described charging zone, being averaged on described at least one zone of charging with Two dimensional Distribution; And

    Ii) be placed on that described charging zone is gone up or during, described electromagnetic field and its coupling when the conductor of described second unit near the placement of described charging zone.
45. 45. according to the described method of claim 44, wherein, the described device that is used to generate an electromagnetic field comprises that at least one is in described charging surface or be basically parallel to the electric conductor that described charging surface carries out Two dimensional Distribution.
46. 46. according to the described method of claim 44, wherein, the described device that is used to generate an electromagnetic field comprises that at least one is wound into the electric conductor to the small part of magnetic conduction bobbin, and described magnetic conduction bobbin is in described charging surface or be basically parallel to described charging surface and carry out Two dimensional Distribution.
47. 47. according to arbitrary described method in the claim 44 to 46, wherein, the durection component that described electromagnetic field lines decomposes on the described charging zone changes in time.
48. 48., wherein, the durection component of the electromagnetic field lines of being decomposed is changed between at least two different directions according to the described method of claim 47.
49. 49., wherein, make the durection component of the electromagnetic field lines of being decomposed move certain angle according to the described method of claim 47.
50. 50., wherein, the durection component of the electromagnetic field lines of being decomposed is rotated according to the described method of claim 49.
51. 51. according to arbitrary described method in the claim 44 to 50, wherein, when the described electromagnetic field lines on the given charging zone projected on the described charging zone, the electromagnetic field lines on the described given charging zone was parallel to each other basically.
52. 52. according to arbitrary described method in the claim 44 to 51, wherein, one the moment net current that described at least one device that is used for generating an electromagnetic field is given when energising flows towards a direction basically.
53. 53. according to arbitrary described method in the claim 44 to 52, wherein, described at least one charging zone is provided with the magnetic material substrate, and wherein said magnetic material is finished a magnetic circuit.
54. 54. according to arbitrary described method in the claim 44 to 53, wherein, described primary device comprises the capacitor of at least one alternative work, be switched on or switched off described capacitor, can change in response to the existence that detects one or more second units so that comprise the electric capacity of the circuit of at least one device that is used to generate an electromagnetic field in the described primary device and described at least one capacitor.
55. 55. according to arbitrary described method in the claim 44 to 54, wherein, be provided with magnetic conductance in described at least one charging zone, the relative permeability of described magnetic conductance is lower than the magnetic permeability that can be arranged on any magnetic core in described at least one second unit.
56. 56. the second unit that a kind and the described system of above-mentioned arbitrary claim, primary device or method are used together, described second unit comprises at least one electric conductor, and has and be roughly laminar form factor.
57. 57. according to the described second unit of claim 56, wherein, described at least one electric conductor twines around magnetic core, described magnetic core is used for flux is arrived wherein.
58. 58. according to the described second unit of claim 57, wherein, described magnetic core is a permeability magnetic material.
59. 59. according to the described second unit of claim 58, wherein, described magnetic core is the amorphous magnetic material.
60. 60. according to the described second unit of claim 59, wherein, described magnetic core is the amorphous magnetic material of non-annealing basically.
61. 61. according to arbitrary described second unit in the claim 57 to 60, wherein, described magnetic core forms flexible band.
62. 62. according to arbitrary described second unit in the claim 56 to 61, wherein, described second unit comprises inductive charging battery pack or battery.
63. 63. according to claim 57 or the described second unit of its arbitrary dependent claims, having thickness is 2mm or littler magnetic core.
64. 64. according to the described second unit of claim 63, having thickness is 1mm or littler magnetic core.
65. 65. according to arbitrary described second unit in the claim 56 to 64, wherein, described second unit has main shaft, and goes up or near described charging when regional when described second unit places described charging zone, in any rotation that its main shaft carries out all with described electromagnetic field couples.
66. 66. according to the described second unit of the claim 65 that is subordinated to claim 62, wherein, described magnetic core twines around the middle body of described battery pack or battery at least in part.
67. 67. according to arbitrary described system in the claim 1 to 25, wherein, described primary device comprises a pair of conductor with adjacent coplane winding, described conductor has the linear segment that is parallel to each other basically and arranges, in order to produce basic uniform electric magnetic field, described electromagnetic field is parallel to the plane of described winding usually and extends, but meets at right angles with described parallel portion basically.
68. 68. according to the described system of claim 67, wherein, described winding forms the scroll shape usually, comprises a series of wire turns with substantially parallel straight portion.
69. 69. according to claim 67 or 68 described systems, wherein, described primary device comprises first pair of conductor and second pair of conductor, these two pairs of conductors are placed in the substantially parallel plane, and the substantially parallel linear segment of described first pair of conductor usually with the substantially parallel linear segment of the described second pair of conductor layout that meets at right angles, described primary device also comprises drive circuit, described drive circuit is used to drive this two pairs of conductors, makes to be created in synthetic that is rotated in the plane that is basically parallel to described winding plane.
70. 70. according to arbitrary described primary device in the claim 26 to 43, comprise a pair of conductor with adjacent coplane winding, described conductor has the linear segment of mutual substantially parallel layout, in order to produce basic uniform electric magnetic field, described electromagnetic field is parallel to the plane of described winding usually and extends, but meets at right angles with described parallel portion basically.
71. 71. according to the described primary device of claim 70, wherein, described winding forms the scroll shape usually, comprises a series of wire turns with substantially parallel straight portion.
72. 72. according to claim 70 or 71 described primary device, comprise first pair of conductor and second pair of conductor, these two pairs of conductors are placed in the substantially parallel plane, and the substantially parallel linear segment of described first pair of conductor usually with the substantially parallel linear segment of the described second pair of conductor layout that meets at right angles, described primary device also comprises drive circuit, described drive circuit is used to drive this two pairs of conductors, makes to be created in synthetic that is rotated in the plane that is basically parallel to described winding plane.
73. 73. one kind basically with reference to the foregoing system that is used to transmit electric energy of the Fig. 4 to Figure 13 in the accompanying drawing.
74. 74. one kind basically with reference to the foregoing primary device that is used to transmit electric energy of the Fig. 4 to Figure 13 in the accompanying drawing.
75. 75. one kind basically with reference to the foregoing method that is used to transmit electric energy of the Fig. 4 to Figure 13 in the accompanying drawing.
76. 76. one kind basically with reference to the foregoing second unit that is used to receive electric energy of the Fig. 4 to Figure 13 in the accompanying drawing.

Images