DE202014010660U1 - Wireless battery charging system for a device with rechargeable battery and with foreign body detection - Google Patents

Abstract

Charging device (20) for inductive power transmission to an energy supply device (300) with a rechargeable battery (326), the charging device (20) comprising: an AC or AC voltage generator (28), which is adapted to an AC electrical power or generate an electrical alternating voltage having a predetermined variable frequency range (502, 602) time-variable frequency (500, 600) and one of the time-variable frequency associated predetermined current or voltage amplitude and to apply a transmitter coil (46) containing transmitter resonant circuit (64), the transmitting coil (46), through which an alternating current is feasible or to which an alternating voltage can be applied, and which is designed to generate a magnetic alternating field, whose field strength varies with the time-variable frequency, under the action of the alternating current or alternating current driven by the alternating voltage applied (500, 600) varies to emit in a predetermined magnetic field irradiation space area (22), characterized by a current and / or a voltage measuring device (74, 66), which is designed as a measurement frequency characteristic (510-512, 608-616) a dependence of an amplitude (504, 604) of a measuring alternating current flowing through the transmitting coil (46) and / or a measuring alternating voltage applied to the transmitting coil (46) of the time-variable frequency (500, 600), and an evaluation device (82) adapted to (a) evaluate a measurement frequency characteristic (510-512, 608-616) with respect to one or more of the following selected characteristic features: (i) a total inductance of the transmitter resonant circuit (64), (ii) a resonant frequency (402, 520) of the transmitter resonant circuit (64), (iii) a current or voltage amplitude (404) of the measured alternating current or AC voltage at the resonant frequency (402), (iv) a current or voltage amplitude itude (504, 604) of the measured alternating current or of the measured alternating voltage at a predetermined measuring frequency (500, 600) contained in the frequency range (502, 502), (v) one of the measuring frequency characteristic (510-512, 608-616 (vi) a parameterizable form of a measurement-frequency characteristic (510-512, 608-616) in the predetermined frequency range (502, 602) and (vii) a correlation of the measurement-frequency characteristic (510-516). 512, 608-616) having a reference frequency characteristic (506, 606) representing a dependence of a reference alternating current flowing through the transmitting coil (46) and / or a reference alternating voltage applied to the transmitting coil of the time-variable frequency, wherein the Reference frequency characteristic (506, 606) has been measured under a condition that the magnetic field irradiation space region (22) is substantially free of an object, and (b) based on an evaluation of at least one of characteristic features (i) to (vii) for the presence of a metal-containing object (26) in the magnetic field irradiation space region (22), wherein the evaluation device (82) is adapted to detect and / or discriminate whether in the magnetic field irradiation room area (22), a device (300) of a predetermined type to be supplied with power, for example a mobile telephone, a smartphone or an audio player, such as an MP3 player, or another type of metal containing foreign body (26 ), such as a coin, a metal foil, a metal ring and / or a paper clip.

Description

The present invention relates to the technical field of a wireless, in particular inductive, battery charging system with a charging device for charging a battery of a battery-powered electrical device.

A conventional battery charging system, which includes a charging device and an energy-supplied, in particular battery-operated, device with a rechargeable battery, which does not require a wire connection between the charging device and the device, can be based on inductive, capacitive or electromagnetic energy transmission or a laser beam, sound, Use compressed air, a liquid jet or a hydraulic system for energy transfer.

The field of wireless power charging or the wireless charging of the batteries of devices such as mobile phones, smart phones or electric vehicles, is an innovative area of activity, in which intensive work is currently being carried out and researched on technological development and further development. As an example of such research and development, reference is made to the work of the Wireless Power Consortium (WPC), an international consortium of companies founded on December 17, 2008, under which a global industrial estate named Qi (Chinese word for "life energy") for the charging of electronic products has been developed and introduced.

An energy transfer, which is based on an inductive coupling between the charging device and the device to be supplied with energy, takes place via a transformer or inductive coupling between a charging coil arranged in the charging coil and a receiving coil arranged in the device to be supplied with energy , In this case, the transmitting coil is subjected to an alternating current, so that it emits an alternating magnetic field, of which the receiving coil "captures" a part of the magnetic alternating current, which induces an alternating voltage in the receiving coil, with a supply or charging current for supplying the device is powered by energy or to charge their battery.

The inductive coupling is particularly efficient when formed in the charging device, the transmitter coil containing a transmitter resonant circuit with a transmitter resonance frequency and when the receiving coil containing a receiving resonant circuit is formed with a receiving resonant frequency, wherein the receiving resonant frequency is tuned to the transmitter resonant frequency. However, if in such an efficiency-optimized battery charging system during the power transmission or charging locally in the vicinity, d. H. In the magnetic field emitting space area of the transmitting coil, foreign matter containing an electrically conductive substance such as a metal, eddy currents are induced in such a foreign body. With regard to the energy to be transmitted, such eddy currents lead to eddy current losses in these foreign bodies and can also cause heating of these foreign bodies. The heat can be transferred to the charging device, for instance to a housing or housing parts of the charging device, and in extreme cases can lead to damage. Furthermore, the energy components removed by eddy current losses and heat are no longer available to the device to be supplied, so that a charging process is prolonged.

The object of the present invention is to provide a battery charging system based on inductive coupling between a charging device and a device to be powered, in which the presence of foreign bodies with metallic components can be detected in the magnetic field transmission area of the transmitting coil.

This object is solved by the subject matters of the independent claims. Advantageous embodiments of the present invention are described in the dependent claims.

According to a first aspect of the invention and as claimed, there is provided a charging device for inductive power transmission to an energy-to-power device having a rechargeable battery. The loading device has the following:
an AC or AC generator configured to generate an AC electrical or AC electrical voltage having a predetermined time and frequency in a predetermined frequency range associated with a predetermined current or voltage amplitude and to apply a transmitter coil containing a transmitter resonant circuit,
the transmitting coil, through which an alternating current can be conducted or to which an alternating voltage can be applied, and which is designed to generate an alternating current, or one of the alternating current, under the effect of the alternating current AC alternating magnetic field generated alternating current field whose field strength varies with the time variable frequency to radiate in a predetermined magnetic field irradiation space area.

• (a) eine Mess-Frequenzkennlinie hinsichtlich eines oder mehrerer, aus den folgenden ausgewählter, charakteristischer Merkmale auszuwerten:
• (i) eine Gesamtinduktivität des Senderesonanzkreises,
• (ii) eine Resonanzfrequenz des Senderesonanzkreises,
• (iii) eine Strom- oder Spannungsamplitude des gemessenen Wechselstroms oder der gemessenen Wechselspannung bei der Resonanzfrequenz,
• (iv) eine Strom- oder Spannungsamplitude des gemessenen Wechselstroms oder der gemessenen Wechselspannung bei einer vorbestimmten, in dem Frequenzbereich enthaltenen Messfrequenz,
• (v) eine aus der Mess-Frequenzkennlinie bestimmte Güte des Senderesonanzkreises,
• (vi) eine parametrisierbare Form einer Mess-Frequenzkennlinie in dem vorbestimmten Frequenzbereich, und
• (vii) eine Korrelation der Mess-Frequenzkennlinie mit einer Referenz-Frequenzkennlinie, die eine Abhängigkeit eines durch die Sendespule fließenden Referenz-Wechselstroms und/oder einer an der Sendespule anliegenden Referenz-Wechselspannung von der zeitvariablen Frequenz darstellt, wobei die Referenz-Frequenzkennlinie unter einer Bedingung gemessen worden ist, dass das Magnetfeld-Bestrahlungsraumgebiet im Wesentlichen frei von einem Gegenstand ist, und
• (b) basierend auf einer Auswertung von mindestens einem der charakteristischen Merkmale (i) bis (vii) auf ein Vorhandensein eines ein Metall enthaltenden Gegenstands in dem Magnetfeld-Bestrahlungsraumgebiet zu schließen.

According to the invention, the charging device further comprises
a current and / or a voltage measuring device, which is designed to measure as a measuring frequency characteristic a dependence of an amplitude of a current flowing through the transmitting coil measuring alternating current and / or applied to the transmitting coil measuring alternating voltage from the time-variable frequency, and
an evaluation device which is designed

• (a) evaluate a measurement-frequency characteristic with respect to one or more of the following selected characteristic features:
• (i) a total inductance of the transmitter resonant circuit,
• (ii) a resonant frequency of the transmitter resonant circuit,
• (iii) a current or voltage amplitude of the measured alternating current or the measured alternating voltage at the resonant frequency,
• (iv) a current or voltage amplitude of the measured alternating current or of the measured alternating voltage at a predetermined measuring frequency contained in the frequency range,
• (v) a quality of the transmitter resonant circuit determined from the measurement frequency characteristic,
• (vi) a parameterizable form of a measurement frequency characteristic in the predetermined frequency range, and
• (vii) a correlation of the measurement frequency characteristic with a reference frequency characteristic representing a dependence of a reference alternating current flowing through the transmitting coil and / or a reference alternating voltage applied to the transmitting coil on the time-variable frequency, wherein the reference frequency characteristic below a Condition that the magnetic field irradiation space region is substantially free of an object, and
• (b) to conclude, based on an evaluation of at least one of the characteristic features (i) to (vii), the presence of a metal-containing article in the magnetic field irradiation space region.

In other words, the charging device further comprises an evaluation device that can evaluate a measurement frequency characteristic with regard to at least one quantity that is influenced by metal in a magnetic field radiation space region. These quantities are mentioned in particular above. The evaluation device ( 82 Further, based on this evaluation, it is able to detect the presence of a metal-containing object in a magnetic field irradiation space region of the transmitting coil.

The evaluation device is further configured to distinguish whether a device to be supplied with energy or another metal object is present in the magnetic field irradiation space region. As a result, in the detection of a device to be powered with the energy transfer (ie with the charging process) can be started or this can be performed while in the detection of another object (ie no device to be supplied with energy, but metal im Irradiation space area before) no energy transfer (ie no charging process) takes place.

An article disposed in the magnetic field irradiation space region containing a metal causes formation of a characteristic feature in the measurement frequency characteristic including, for example, a change in the shape of the frequency characteristic, that is, a frequency detuning. H. a change in the resonant frequency of the transmitter resonant circuit, particularly in comparison with a reference frequency characteristic measured under the condition that the magnetic field irradiation room area is free of foreign matter. In other words, a metal-containing article disposed in the magnetic field irradiation space region causes a measurement frequency characteristic of the transmitter resonant circuit to exhibit one or more of the above characteristics in a reference frequency characteristic of the transmitter resonant circuit in the condition that Magnetic field irradiation space area no object is present, is not included.

A characteristic feature can be determined by evaluating a measurement frequency characteristic of the transmitter resonant circuit. On the basis of such determination, it may then be concluded that there is a metal-containing article in the magnetic field irradiation space region.

A body in which no eddy current is induced, such as a body made of an electrically non-conductive material and disposed in the magnetic field irradiation space region, may be connected to the body Inventive charging device or the evaluation of a frequency characteristic according to the invention are not detected reliably.

The evaluation device can be designed to detect and / or to distinguish whether in the magnetic field irradiation space area an energy-to-be-supplied device of a predetermined type, for example a mobile phone, a smartphone or an audio player, such as an MP3 player, or another type of metal-containing foreign substance such as a coin, a metal foil, a metal ring and / or a paper clip.

The evaluation device can also be designed to detect and / or to discriminate based on an evaluation of the change of the resonance frequency and / or the quality, whether in the magnetic field irradiation space area an energy-to-be-supplied device of a predetermined type or a different, a metal containing foreign body is present.

In a memory device contained in the charging device, for example in the evaluation device, a first and second, predetermined Resonanzfrequenzschwellwert and a first and second, predetermined Güteschwellwert be stored. At these values, the second resonant frequency threshold is greater than the first resonant frequency threshold and the second threshold value is greater than the first threshold value. These values are empirically chosen such that a comparison of resonant frequency and transient response measurements with these thresholds is different for the presence of an energized device, a foreign body, or no foreign matter in the magnetic field irradiation space region.

In one, for example, empirically determined embodiment, the evaluation device may be configured, if the resonance frequency is greater than the second resonance frequency threshold and the quality is less than the first Güteschwellwert to detect that in the magnetic field irradiation space area, a foreign metal containing a foreign body of a is supplied with electrical energy to be supplied device of one of the predetermined types, is present.

In another, for example, also empirically determined embodiment, the evaluation can be designed to detect that in the magnetic field irradiation space area, if the resonance frequency is greater than the first and smaller than the second Resonanzfrequenzschwellwert and the quality is greater than the second Güteschwellwert energy-supplied device of one of the predetermined types is available.

In the loading device may further be provided an output device. This can be operatively coupled to the evaluation device and be configured such that, when the evaluation device has detected that in the magnetic field irradiation space region, a metal-containing foreign body which is different from a device to be supplied with electrical energy of one of the predetermined types, is present, can issue a warning signal indicative of this detected circumstance. The output signal may be an output, such as a font output, on a display device, an optical signal, or even an audible signal. When a user perceives the notification signal, he can remove the foreign substance from the magnetic field irradiation room area.

The magnetic field irradiation space area can be limited at least in sections by means of a mechanical wall. In this case, the wall may in particular have a shape of a spherical section, an ellipsoidal section, a cone, a shell or else a substantially planar surface. The shape of the wall may be adapted to an outer shape of a device to be operated together with the loading device, for example, such that the device is supported and / or supported by the wall.

The charging device may further include a capacitor having a capacitance. The capacitor may be connected to the transmit coil in series or parallel connection. This can be formed from the capacitor and the transmitting coil towards transmitter resonant circuit. The value of the capacitance and the value of the inductance can be matched to one another such that this series or parallel circuit or the transmitter resonant circuit has a predetermined resonant frequency.

According to a second aspect of the invention, and as also claimed, there is provided an energized device having a rechargeable battery and adapted for use in inductive coupling with a charging device according to the first aspect of the invention.

The device may be a mobile phone, a smartphone or an audio player, such as an MP3 player.

Alternatively, the device may be an electric vehicle, wherein the rechargeable battery is a driving battery of the electric vehicle.

The apparatus may include a rectifier having first and second AC input and first and second DC output and a receiving coil connected in series between the first and second AC input. In this case, the rechargeable battery in series between the first and second DC voltage output can be switched, in particular switched.

According to a third aspect of the invention, and as also claimed, there is provided a battery charging system comprising a charging device according to the first aspect of the invention and an energized device according to the second aspect of the invention. The charging device is designed for inductive transmission of energy to the device, in particular for charging its battery.

In the battery charging system, the charging device may include a capacitor having a capacitance connected in series with the transmitting coil or a parallel circuit, thereby forming a transmitter resonant circuit, and wherein the value of the capacitance and the value of the inductor are matched to each other Series or parallel circuit or the transmitter resonant circuit has a predetermined resonant frequency. The device to be energized may include a receiving circuit capacitor connected in series or in parallel with the receiving coil, thereby forming a receiving resonant circuit. In this case, an inductance of the receiving coil and a capacitance of the receiving circuit capacitor can be coordinated so that a resonant frequency of the series or parallel connection of the receiving coil and the receiving circuit capacitor or a resonant frequency of the receiving resonant circuit substantially equal to the resonant frequency of the series or parallel connection of the transmitting coil and the capacitor or the transmitter resonant circuit of the charging device is.

It should be noted that embodiments of the invention have been described with reference to different subject matters. However, it will be readily apparent to those skilled in the art upon reading this application that, unless explicitly stated otherwise, in addition to a combination of features belonging to a type of subject matter, any combination of features that may result in different types of features is also possible Subject matters belong.

Further advantages and features of the present invention will become apparent from the following exemplary description of presently preferred embodiments.

1 shows a schematic block diagram of an embodiment of a battery charging system with a first embodiment of a charging device and a device to be powered according to the invention.

2 shows a schematic block diagram of a second embodiment of a charging device according to the invention.

3 shows a schematic block diagram of a third embodiment of a charging device according to the invention.

4 shows a schematic representation of an experimental structure of yet another embodiment of a charging device according to the invention, wherein a foreign body in the magnetic field irradiation space region of the transmitting coil can be arranged.

5 shows a bar graph with measurement results, by means of the construction of the 4 have been obtained for a plurality of different, arranged in the magnetic field irradiation space area of the transmitting coil foreign body.

6 shows a schematic representation of a frequency characteristic of a resonance circuit containing a coil and a capacitor, illustrating the determination of measured values for the resonance frequency and the quality.

7 shows a representation of a reference frequency characteristic and two measuring frequency characteristics, with two different bodies in the magnetic field irradiation space region of the transmitting coil by means of the structure of the 4 been recorded.

8th FIG. 10 is a diagram showing a reference frequency characteristic and measurement frequency characteristics of various bodies in the magnetic field irradiation space region of the transmitting coil by means of the structure of FIG 4 been recorded.

9 FIG. 12 is a diagram showing a reference frequency characteristic and measurement frequency characteristics associated with a body located at different positions in the magnetic field irradiation space area of the transmitting coil by means of the structure of FIG 4 been recorded.

It should be noted that the embodiments described below represent only a limited selection of possible embodiments of the invention. Thus, it is possible to suitably combine the features of individual embodiments with one another, so that for the person skilled in the art with the variants of embodiment that are explicit here, a multiplicity of different embodiments are to be regarded as obviously disclosed.

This in 1 shown, wireless battery charging system 10 includes a charging device 20 according to the invention and a device to be supplied with energy 300 that are inductively coupled together so that the charging device 20 via the inductive coupling 12 Energy to the device 300 can transfer.

The loading device 20 has an AC and sweep generator 28 , an amplifier 36 , a transmitter resonant circuit 64 that's from a transmitting coil 46 and a capacitor 52 is formed, a voltage measuring device 66 , a current measuring device 74 , an evaluation device 82 , a control device 84 , a storage device 86 and an output device 88 on. The AC and sweep generator 28 is adapted to an alternating electrical current with a in a predetermined frequency range 502 . 602 (please refer 7 . 8th and 9 ) time-variable frequency 400 . 600 and to generate a predetermined current amplitude associated with the time-varying frequency and via its first and second output terminals 30 and 32 issue. The generator 28 has a generator control input 34 via which a generator control signal can be supplied to it. The generator control signal is in the control device 84 generates and controls the time-dependent frequency and the amplitude of the generated alternating electrical current.

The amplifier 36 causes a power amplification of that of the AC and sweep generator 28 generated AC power and is a power amplified AC to operate the transmitter coil 46 out. The amplifier 36 has a first and a second entrance 38 and 40 connected to the first and second output terminals 30 and 32 of the alternator 28 , respectively, are connected, and about him that from the generator 28 generated alternating current signal with time-dependent frequency is supplied. The amplifier 36 also has a first and a second output 42 and 44 between which it provides the power amplified alternating current and into the transmitter resonant circuit 64 feeds. The amplifier 36 also has an amplifier control input 45 via which an amplifier control signal can be supplied to it. The amplifier control signal is also in the controller 84 generated; it controls the gain (amplitude gain) of the amplifier 36 supplied alternating current.

The transmitter resonant circuit 64 is as a series connection of the capacitor 52 and the transmitting coil 46 executed. In the series circuit is also the current measuring device 74 in series with the transmitting coil 46 connected. For forming transmitter resonant circuit 64 is a first connection 54 of the capacitor 52 with the first exit 42 of the amplifier 36 , a first connection 48 the transmitting coil 46 with the second connection 56 of the capacitor 52 , a second connection 50 the transmitting coil 46 with a first connection 76 the current measuring device 74 and a second connection 78 the current measuring device 74 with the second exit 44 of the amplifier 36 electrically connected. By the integration of the current measuring device 74 in the series connection of the capacitor 52 and the transmitting coil 46 is the current measuring device 74 capable of passing through the transmitting coil 46 to measure driven alternating current.

The tension measuring device 66 is parallel to the transmitting coil 46 connected. This is a first connection 68 the tension measuring device 66 with the first connection 48 the transmitting coil 46 and a second connection 70 the tension measuring device 66 with the second connection 50 the transmitting coil 46 electrically connected. Through this parallel connection of the voltage measuring device 66 with the transmitting coil 46 is the voltage measuring device 66 capable of acting on the transmitting coil 46 to measure applied AC voltage.

Alternatively, the voltage measuring device could 66 also parallel to the capacitor 52 be switched so that they are capable of connecting to the capacitor 52 to measure applied AC voltage. In this case, the evaluation of parameters of the capacitor 52 measured frequency characteristics adapted to adapt or modify compared to the evaluation of parameters of the transmitting coil 46 measured measurement frequency characteristics.

The one from the amplifier 36 provided, power amplified alternating current is through the transmitting coil 46 passed through. Thus, the transmitting coil 46 capable of generating a magnetic alternating field generated under the action of said alternating current in a predetermined magnetic field irradiation space area 22 radiate. The field strength of the transmission coil 46 generated, alternating magnetic field varies with the time-variable frequency 300 . 400 (please refer 7 . 8th and 9 ).

The magnetic field irradiation area 22 is in sections by means of a mechanical wall 24 defined or limited. The wall 24 has a shape of a shell in the embodiment shown. This shape is to the shape of a housing portion of the loading device 20 inductively coupled and so to be supplied with energy device 100 adjusted, so the device 100 through from the bowl-shaped wall 24 received and supported by this.

The current measuring device 74 is designed as a measuring frequency characteristic (see, for example, 510 . 512 in 7 and 608 to 616 in the 8th and 9 ) the dependence of the amplitude 504 . 604 by the transmitting coil 46 flowing alternating current of the time-variable frequency (see eg 500 in 7 and 600 in the 8th and 9 ) to eat. Accordingly, the voltage measuring device 66 designed as an alternative measuring frequency characteristic, the dependence of the amplitude of the transmitting coil 64 measured alternating current voltage to be measured by the time-variable frequency.

The control device 84 is designed to be the alternator 28 and the amplifier 36 head for. More specifically, the controller is 84 capable of the alternator 28 via its generator control input 34 Supply control signals that control the current amplitude and frequency, including the time dependence of the frequency, and also the amplifier 36 via its amplifier control input 45 To supply a control signal that the (power) amplification factor of the amplifier 36 controls.

The time dependence of the frequency of the from the alternator 28 AC current generated may suitably have a sawtooth waveform with a periodic sequence including a time linear increase in frequency and a fast, substantially instantaneous frequency decrease (not shown). Such time-dependence of the frequency is also called frequency sweep. During the time-linear increase of the frequency, the frequency sweep covers a frequency range (see 502 in 7 and 602 in the 8th and 9 ) defined by a minimum frequency and a maximum frequency.

In the following with reference to 4 to 9 described measuring examples is the minimum frequency 40 kHz and the maximum frequency 240 kHz. In the in 4 shown measuring structure is as a transmitting coil 46 a coil arrangement having a spiral conductor arranged substantially in a plane electrical conductor wire, a so-called Litz-wire antenna 47 , used. The Litz-Wire antenna 47 is in series with a capacitor 46 with a capacitance of 94 nF (nano Farad) and forms a transmitter resonant circuit with a resonant frequency f _res of nominally about 110 kHz, ie a value in the frequency range 502 . 602 from 40 kHz to 240 kHz is included.

The evaluation device 82 is adapted to that of the tension measuring device 66 measured value of the amplitude of the AC voltage, you via the voltage measurement signal line 72 is supplied, and to receive the time dependence of the amplitude of the AC voltage and in the memory device 86 to save for further evaluations. Furthermore, the evaluation device 82 designed to, even those of the current measuring device 72 measured value of the amplitude of the alternating current, you through the current measurement signal line 80 is supplied, and to receive the time dependence of the amplitude of the alternating current and also in the memory device 86 to save for further evaluations.

The evaluation device 82 is further configured as a reference frequency characteristic (see the curve 506 in 7 and the curve 606 in the 8th and 9 ) a dependency of one through the transmitting coil 46 flowing reference alternating current and / or a voltage applied to the transmitting coil reference AC voltage from the time-variable frequency in the memory device 86 save. The designation of this measurement as a "reference" means that the reference frequency characteristic 506 . 606 is measured under a condition where the magnetic field irradiation room area 22 the transmitting coil 46 essentially free of a foreign body 26 is.

The evaluation device 82 is further adapted, according to the function (a) mentioned in claim 1, a measuring frequency characteristic (see the curves 510 to 512 in 7 and the curves 608 to 616 in the 8th and 9 ), for example, under a condition that an object such as a foreign object 26 or a device to be supplied with energy 300 in the magnetic field irradiation area 22 the transmitting coil 46 is arranged, the measurement frequency characteristic in the memory device 86 to evaluate the measurement frequency characteristic with respect to the occurrence of one or more characteristic features which may be selected from the following: (1) a total inductance of a transmitter resonant circuit 64 , (ii) a resonant frequency 402 (please refer 6 ) respectively. 520 (please refer 5 ) of a transmitter resonant circuit 64 , (iii) a current or voltage amplitude of the measured AC or measured AC voltage at the resonant frequency 402 respectively. 520 , (iv) a current or voltage amplitude 504 . 604 the measured alternating current or the measured alternating voltage at a predetermined, in the frequency range 502 . 602 contained measuring frequency 500 . 600 , (v) one of a frequency characteristic (see the curves 506 and 510 to 512 in 7 and the curves 606 and 608 to 616 in the 8th and 9 ) the quality of the measurement frequency characteristic 522 , (vi) a parameterizable form of a measurement frequency characteristic (or a reference frequency characteristic) in the predetermined frequency range 502 . 602 , and (vii) a correlation of the measurement frequency characteristic 510 - 512 . 608 - 616 with a reference frequency characteristic 506 . 606 that has a dependence of one through the transmitting coil 46 representing reference alternating current and / or a reference coil voltage applied to the transmitting coil of the time-variable frequency, wherein the reference frequency characteristic 306 . 406 has been measured under a condition that the magnetic field irradiation space area 22 is essentially free of an object.

Furthermore, the evaluation device 82 generally adapted to close according to the function (b) mentioned in claim 1, based on an evaluation of at least one of the characteristic features (i) to (vii) for the presence of an object containing a metal.

In particular, and as will be shown below with reference to measuring examples, the evaluation device 82 adapted to detect in an embodiment of the function mentioned in claim (b), from an evaluation of characteristic features of the measurement frequency characteristic or a comparison of the characteristics of the measurement frequency characteristic with the frequency-frequency characteristic and / or to distinguish whether in the magnetic field irradiation room area 22 a device to be supplied with energy 300 of a predetermined type or type of foreign metal containing a metal 26 , is available.

In one embodiment of the loading device 20 Can the loader 20 device to be supplied with energy 100 a mobile phone, a smartphone or an audio player, such as an MP3 player, so a portable or with a user's hand portable or mobile small device to be. Here is the loading device 20 for use under room conditions, ie "indoor", such as in an office environment. In this case, the foreign body containing a metal 26 For example, be a coin, a metal foil, a metal ring and / or a paper clip.

In another embodiment, that of the loading device 20 device to be supplied with energy 300 be an electric vehicle whose traction battery is to be charged. Here is the loading device 20 intended for outdoor use, ie "outdoor". In this case, the foreign body containing a metal 26 a metal sheet or a body part of the vehicle.

measurement Examples

The invention has been exemplified with an experimental setup of a charging device 20 who in 4 is shown schematically executed. Indian in 4 shown embodiment included the "loader" 20 as an alternator 28 a signal generator of the type Agilent 33220A, as this downstream amplifier 36 a half-bridge power amplifier type APEX PA16 and one of the amplifier 36 fed transmitter resonant circuit, which in one embodiment, a capacitor 52 with a capacitance C of nominal C = 94 nF and in another embodiment no capacitor, and in each Case a transmitting coil 46 acting as a helical stranded wire antenna 47 was formed with a diameter of about 4 cm included. In the transmitter resonant circuit was an AC meter with the transmitter coil 46 connected in series, as in the 1 is shown. A personal computer (not shown) has been used to read in the current measurements produced by the AC meter and the associated (time-dependent) frequencies of the AC generated by the signal generator, and thus to record time dependencies of the amplitude of the AC, and also the time dependencies in dependence of the AC amplitude on the frequency ie, reference and measurement frequency characteristics, to be converted and stored in a memory device (not shown) of the personal computer.

First series of measurements

With the above described and in 4 In the embodiment without capacitor in the transmitter resonant circuit and in the manner described above, frequency characteristics were recorded for the following on the Litz wire antenna 47 ie "in the magnetic field irradiation space area of the antenna 47 ", Arranged samples: 540 Sample # 0: Reference measurement, without launched object 542 Sample # 1: Google Nexus ^® 5 smartphone 544 Sample # 2: Smartphone of the type iPhone ^® 5 546 Sample # 3: Samsung S3 ^® mini smartphone (without WPC or Qi charging function) 548 : Sample # 4: Coin of the kind 5 euro cents 550 : Sample # 5: Coin of the kind 1 euro 552 : Sample # 6: Coin of the type 2 Euro 554 : Sample # 7: Coin of the type 50 Euro cent 556 : Sample # 8: Coin of type 2 Euro (sample # 6) together with smartphone Google Nexus 5 (sample # 1)

7 shows as reference frequency characteristic 506 the frequency characteristic of the reference measurement 540 ie without one on the coil 47 and further exemplified as a first measurement frequency characteristic 510 the frequency characteristic associated with sample # 2 ( 544 ) and as a second measurement frequency characteristic 512 the frequency characteristic associated with sample # 6 ( 552 ) has been recorded. From the reference frequency characteristic 506 can be read that the resonant frequency of the transmitter resonant circuit in the "charging device" 20 out 3 at 121 kHz and that the frequency characteristic has a pronounced peak with a relative, ie in comparison to the characteristics 510 and 512 having small width. From a comparison of the first and second measurement frequency characteristics 510 and 512 with the reference frequency characteristic 506 can be read that when placing the respective samples, the resonance frequency increased and the width of the peak of the characteristic increased.

Overall, for each of the aforementioned samples, a measurement frequency characteristic of the in 7 recorded kind. In the process, a fixed frequency of 110 kHz, which was the same for all samples, was specified by the alternating current generator used.

The measurement frequency characteristics were evaluated with regard to the value of the resonance frequency f _res and one of the width Δf = | f ₂ -f ₁ | of the peak of the characteristic derived quantity, namely the so-called quality (symbol Q) of the transmitter resonant circuit. These evaluations are in 6 based on a schematic frequency characteristic 400 shown and explained below. The quality Q of a transmitter resonant circuit is generally defined as the quotient of the maximum, ie the level A ₀ ( 404 ) of the frequency characteristic read resonant frequency f _res ( 402 ) and the width Δf = | f ₂ -f ₁ | the peak of the frequency characteristic: Q = f _res / Δf = f _res / | f ₂ -f ₁ | (1)

The width Δf = | f ₂ -f ₁ | the peak of the frequency characteristic is at a level of proportional 1 / √2 = 0.707 of the maximum level A ₀ ( 404 ) of the peak, ie at one level 406 from A ₀ / √2 = A ₀ × 0.707 (2) as the difference of this level 406 associated frequencies f ₁ ( 408 ) and f ₂ ( 410 ).

For sample # 0, the reference frequency characteristic became 506 and for each of Samples # 1 to # 8, a measurement frequency characteristic is recorded. Furthermore, the (modified) inductance L of the transmitting coil without or with applied sample and the series resistance R of the transmitting resonant circuit were measured. The quality was determined from the frequency characteristics. Finally, for each sample, the known relationship between the resonant frequency f _res , the (altered) inductance L and the capacitance C of the resonant circuit, namely the relationship ω ² = 2πf _res = 1 / LC ⇔ f _res = 1 / (2π × √LC) (3) the (changed) resonance frequency f _res of the transmission resonant circuit calculated. The results thus obtained are summarized in Table 1. In the bar chart of the 5 For each of the samples # 0 to # 8, the quality Q taken from Table 1 and the resonant frequency f _{res of} the transmitter resonant circuit are shown graphically. Table 1: Measured values from the first series of measurements # sample position L [μH] R [mΩ] Q f _res [kHz] 0 without 18.47 95 133 120.2 1 Nexus 5 center 21.38 283 51 111.7 2 iPhone center 16.04 185 59 128.9 3 Samsung S3 mini center 13.3 325 30 141.6 4 5 cents center 14.6 838 12.1 135.1 5 1 € center 13.9 486 19.8 138.5 6 2 euros center 13.4 720 12.9 141.1 7 50 cents center 12.6 543 16.2 145.5 8th 2 euros + Nexus 5 center 12.3 989 8.79 147.2

It is noted that Samples 1 and 2 are smartphones exemplifying a device to be energized 300 are and have a wireless power charging device suitable according to the aforementioned Qi standard of the company consortium WPC. Accordingly, these have a reception resonant circuit 314 (please refer 1 ) with a built-in receiver coil 302 , which in their geometric shape disc-shaped and thus similar to the used in the measuring arrangement Litz wire antenna 47 is shaped. The "arranging the device 300 in the magnetic field irradiation area 22 the transmitting coil 46 "Was done by placing the respective smartphone on the Litz wire antenna 47 , wherein the receiving coil 302 relatively close to the transmitting coil 46 came and was arranged parallel to this (just like this in 3 right), resulting in effective inductive coupling and a particularly pronounced influence of the device 300 (Smartphone of the types mentioned) on the frequency characteristic causes. In contrast, the smartphone (type Samsung S3 mini) of Probe 3 did not include a wireless charger, so no built-in receiver coil 302 a reception resonant circuit 314 , whereby for this sample 3 a lesser influence on the (change of) the frequency characteristic is to be expected.

• (1) Wenn ein Gegenstand, der ein Metall bzw. metallisches Material enthält, im Magnetfeld-Bestrahlungsraumgebiet der Sendespule 46 (hier: Litz-Wire-Antenne 47) angeordnet ist, dann verändert sich die Gesamtinduktivität L des Systems bestehend aus der Sendespule und dem in ihrem Bestrahlungsraumgebiet angeordneten Gegenstand, erhöht sich die Resonanzfrequenz f_res des Senderesonanzkreises und verringert sich dessen Güte Q bzw. vergrößert sich die Breite des Resonanzpeaks der Frequenzkennlinie. Somit ist prinzipiell das Vorhandensein eines Fremdkörpers im Magnetfeld-Bestrahlungsraumgebiet der Sendespule durch eine Auswertung bzw. Messung der Änderung der Gesamtinduktivität L, der Resonanzfrequenz f_res oder der Güte Q möglich.
• (2) Wenn der Gegenstand ein Smartphone ist (Proben #1 bis #3), nimmt die Güte Q zwar ab, jedoch weniger stark als wenn die Probe ein massives Metallstück (Münze) ist (Proben #4 bis #8). Somit kann durch Wählen von geeigneten Schwellwerten (erster Güteschwellwert 528 und zweiter Güteschwellwert 530) unterschieden werden, ob es sich bei dem Gegenstand um ein Smartphone (Proben #1 bis 443, als Beispiel eines mit Energie zu versorgenden Geräts 300) oder um eine Münze (Proben #4 bis #8, als Beispiel für einen massiv-metallischen Fremdkörper 26) handelt.

In an overview of those listed in Table 1 and in 5 The results summarized below can be summarized.

• (1) When an article containing a metal or metallic material is in the magnetic field irradiation space region of the transmitting coil 46 (here: Litz wire antenna 47 ), then the total inductance L of the system consisting of the transmitting coil and the object arranged in its irradiation area changes, the resonant frequency f _{res of} the transmitter resonant circuit increases and the quality Q thereof decreases or the width of the resonance peak of the frequency characteristic increases. Thus, in principle, the presence of a foreign body in the magnetic field irradiation space area of the transmitting coil is possible by evaluating or measuring the change in the total inductance L, the resonant frequency f _res or the quality Q.
• (2) If the item is a smartphone (Samples # 1 to # 3), Q will decrease but less so than if the sample is a solid piece of metal (coin # 4 to # 8). Thus, by choosing appropriate thresholds (first threshold value 528 and second quality threshold 530 ), whether the item is a smartphone (samples # 1 to 443 , as an example of a device to be powered 300 ) or a coin (Samples # 4 to # 8, as an example of a solid-metallic foreign body 26 ).

From Table 1 and 5 can be read, that for the first measurement series a first (lower) value threshold value 528 of about 20 can be defined, with the meaning that a measured, reduced quality Q, which is smaller than the first quality threshold 528 is for the presence of a coin (Samples # 4 to # 8, as an example of a solid-metallic foreign body 26 ) in the irradiation space area of the transmitting coil.

• (3) Wenn der Gegenstand ein massives Metallstück (Münze, Proben #4 bis #8) ist, dann steigt die Resonanzfrequenz f_res an, und zwar stärker als wenn die Probe ein Smartphone mit einer Drahtlos-Ladeeinrichtung (Proben #1 und #2) ist. Somit kann durch Wählen von geeigneten Schwellwerten (erster Resonanzfrequenzschwellwert 524 und zweiter zweiter Resonanzfrequenzschwellwert 526) unterschieden werden, ob es sich bei dem Gegenstand um ein Smartphone mit einer Drahtlos-Ladeeinrichtung (als Beispiel eines mit Energie zu versorgenden Geräts 300) oder um eine Münze oder einen Gegenstand mit in der Form von Elektronik-Schaltkreisen eingeführtem Metall (als Beispiel für einen ein Metall enthaltenden Fremdkörper 26) handelt.

From Table 1 and 5 is also read that for the first measurement series, a second (higher) Güteschwellwert 330 30 can be defined with the meaning that a measured, compared to the reference reduced quality Q, but greater than the second Güteschwellwert 530 is for the presence of a smartphone (samples # 1 to # 3, as an example of a device to be powered 300 ) in the irradiation room area 22 close the transmitter coil.

• (3) If the article is a solid piece of metal (coin, samples # 4 through # 8), then the resonant frequency f _res increases more than if the sample is a smartphone with a wireless charger (samples # 1 and # 2 ). Thus, by choosing appropriate thresholds (first resonant frequency threshold 524 and second second resonant frequency threshold 526 ), whether the item is a smartphone with a wireless charger (as an example of a device to be powered 300 ) or a coin or an article having metal introduced in the form of electronic circuits (as an example of a metal-containing foreign body) 26 ).

For the first measurement series, a first (lower) resonant frequency threshold value can be set 524 130 kHz, with the meaning that a measured resonant frequency, although higher than the reference resonant frequency, but smaller than the first Resonanzfrequenzschwellwert 524 is the presence of a smartphone with a wireless charger (samples # 1 and # 2, as an example of a device to be powered up 300 ) in the irradiation room area 22 close the transmitter coil.

Furthermore, a second (higher) resonance frequency threshold value can be set for the first measurement series 526 of about 135 kHz, with the meaning that a measured resonant frequency is higher than the second resonant frequency threshold 526 is for the presence of a coin or an object having metal introduced in the form of electronic circuits (Samples # 3 to # 8) as examples of a metal-containing foreign body 26 ) in the irradiation room area 22 close the transmitter coil.

Those skilled in the art will appreciate that such thresholds as the first and second resonant frequency thresholds 524 and 526 and the first and second threshold values 528 and 530 the design (eg shape and geometry) of the transmitting coil, the geometry of the irradiation room area, the possible arrangements (inter alia distance and solid angle direction) of objects in the irradiation space area or in relation to the transmitting coil and of the type of object (eg metal content, Metal type) and therefore for each embodiment of a charging device 20 in terms of the design of the transmitting coil 46 and the magnetic field irradiation room area 22 must be empirically determined (predetermined) in order to enable at least a detection of the presence of a (foreign) body or even a distinctness of the type of existing in the irradiation space area object.

More generally, the evaluation device is 82 configured based on an evaluation of the change in the resonant frequency 402 (please refer 6 ) respectively. 520 (please refer 5 ) and / or the goodness 522 (please refer 5 ) to detect and / or distinguish whether in the magnetic field irradiation space region 22 a device to be supplied with energy 300 a predetermined type or other type of metal containing foreign body 26 is available.

Second series of measurements

With a charger 20 according to the in the 4 shown circuit principle, wherein the transmitter resonant circuit 64 as a transmitting coil 46 the same Litz wire antenna 47 as contained in the first series of measurements and also a capacitor 52 with constant capacity of 94 nF were in a second Series of measurements still other types of foreign bodies in the magnetic field irradiation space area 22 the Litz wire antenna 47 arranged and each recorded an associated measurement frequency characteristic. The results, ie a reference frequency characteristic 606 and the first to fifth measurement frequency characteristics 606 to 616 , are in the 8th and 9 shown. The second series of measurements was aimed at recording measurement frequency characteristics of different types of metal and measuring frequency characteristics for different positions of a same object with respect to the transmitter coil and for identifying characteristics in the recorded frequency characteristics that could discriminate the type of metal or metal Enable position.

The in the 8th and 9 shown frequency characteristics 606 to 616 the following items or samples are assigned: Frequency characteristic 606 : Reference frequency characteristic (without object) Frequency characteristic 608 : 1 EUR coin, in the middle on spool 47 Frequency characteristic 610 : Google Nexus 5 with charge-receiving coil Frequency characteristic 612 : aluminum sheet Frequency characteristic 614 : 1 EUR coin, in the middle on spool 47 Frequency characteristic 616 : 1 EUR coin, on the edge of the coil 47

In the second series of measurements, a total of measurement-frequency characteristics of the aforementioned and still further objects were recorded. To characterize the measurement frequency characteristics, the parameters resonant frequency f _res (see 402 in 6 ) and maximum amplitude A ₀ (see 404 in 6 ) read. The results are summarized in Table 2 below. Table 2: Measured values from the second series of measurements Sample No. object Frequency characteristic line f _res [kHz] A ₀ [dB] 0 Without (reference) 606 119 -19 1 1 EUR coin in the middle 614 139 -33 2 2 EUR coin in the middle 146 -29 3 50 EUR Cent in the middle 143 -32 4 Google Nexus 5 with charge-receiving coil 610 110 -36 5 aluminum sheet 612 225 -34 6 tinplate 150 -19 7 copper sheet 173 -30 8th aluminum foil 123 -25 0 Without (reference) 606 119 -19 9 1 EUR coin in the middle 614 139 -33 10 1 EUR coin between center and edge 135 -34 11 1 EUR coin on the edge 616 128 -34

From a comparison of the measurement results for the sample Nos. 0 and 1 to 8, it can be seen that the resonant frequency of the transmitter resonant circuit with that by the presence of the sample object in the magnetic field irradiation space area 22 the Litz wire antenna 47 changed inductance for each item has a different value. This implies that it should be possible to deduce, based on a determination of the resonant frequency, the type of article and / or the metal species of metal contained in the article.

From a comparison of the measurement results for samples Nos. 0 and 9 to 11, it can be seen that the influence of the object on the frequency characteristic is continuous with the distance of the object from the transmitting coil 46 decreases. As the distance increases (sample 9 → 10 → 11), the resonance frequency f _res and also the maximum amplitude A ₀ decrease continuously. This implies that it should be possible, on the basis of a determination of at least the parameters resonant frequency f _res and maximum amplitude A ₀ investigated here, to conclude an approximation of a metal-containing object at short intervals in the event of continuous change.

The evaluation device 82 is operative with the output device 88 coupled. The output device 88 is designed to when the evaluation 82 has detected that in the magnetic field irradiation space area 22 an object is present, a warning signal 90 which indicates this detected circumstance. If a distinctness of objects is possible, for example through empirically tested evaluation algorithms or evaluation criteria, the output device can 88 be designed so that when the evaluation 82 has detected that in the magnetic field irradiation space area 22 a metal-containing foreign body 26 , of a device to be supplied with energy 100 is different from one of the predetermined types, there is another indication signal 90 which indicates this detected circumstance. The output signal may be an output (such as a font output) on a display device, an optical signal or even an acoustic signal. When a user perceives the alert signal, he or she may recognize the (recognized) foreign object 26 from the magnetic field irradiation room area 22 the transmitting coil 46 remove.

The reference frequency characteristic 506 . 606 , the first and second predetermined resonant frequency thresholds 524 and 526 , the first and second predetermined threshold values 528 and 530 and, if appropriate, other suitable sizes or threshold values for the recognition of an object, the recognition of a foreign body and / or the differentiation of objects are in the storage device 86 saved. The second resonance frequency threshold 526 in any case, it is greater than the first resonance frequency threshold value 524 and the second quality threshold 530 greater than the first quality threshold 528 such that bandwidths for the resonant frequency and / or the quality can be defined and predetermined.

Based on the first series of measurements, it was shown by way of example that the evaluation device 82 can be formed so that when the resonance frequency 520 greater than the second resonant frequency threshold 526 and the goodness 522 smaller than the first quality threshold 528 is to conclude that in the magnetic field irradiation room area 22 a metal-containing foreign body 26 , of a device to be supplied with energy 300 is different from one of the predetermined types is present.

Also exemplified has been that the evaluation 82 can be formed when the resonant frequency 520 bigger than the first 524 and smaller than the second 526 Resonant frequency threshold and the quality 522 greater than the second quality threshold 530 is to conclude that in the magnetic field irradiation room area 22 a device to be supplied with energy 300 of one of the predetermined types is present.

The device to be supplied with energy 300 becomes inductive coupling 12 with a charger 20 ie, in the magnetic field irradiation room area 22 the transmitting coil 64 the loader 20 brought as in 1 indicated to transfer energy via this coupling. Typically, the device uses 300 the energy transferred to charge a rechargeable battery contained in it 126 ,

The principle of foreign object recognition according to the present invention may be for a charging device 20 or 120 (please refer 1 and 2 ) which is to transmit a relatively small power, such as a relatively small mobile device 300 , which may be a mobile phone, a smartphone or an audio player such as an MP3 player. The inventive principle can also be used in a charging device 220 be realized, which is to transmit a relatively large power (see 3 ), for example, when the device 300 an electric vehicle and the rechargeable battery 326 is a driving battery of the electric vehicle.

According to the principle of inductive coupling, the device comprises 300 a receiver coil 302 for "catching" part of the flow of the coil from the transmitter 64 the loader 20 generated and emitted, alternating magnetic field. Because the receiver coil 302 Providing energy in the form of an alternating electric field induced by the alternating magnetic field, it is necessary that in the receiving coil 302 to convert converted AC voltage into a DC electrical voltage, so like this to charge a battery 326 is required. This includes the device 300 a rectifier 316 , The rectifier 316 has a first and a second AC input 318 and 320 and a first and a second DC voltage output 322 and 324 , The receiver coil 302 is in series between the first AC input 318 and the second AC input 320 connected. The rechargeable battery 326 is in series between the first DC output 322 and the second DC voltage output 324 connected.

Similar to a transmitter tone circle 64 , which is tuned to a predetermined transmission frequency, in the charging device 20 is provided also has the device to be supplied with energy 300 a reception resonant circuit 314 , the receiver coil 302 and a receiving circuit capacitor 308 includes. The receiving circuit capacitor 308 can with the receiving coil 302 be connected in series, as in the 1 is shown, or it can be parallel to the receiving coil 302 be connected (not shown) to the receive resonant circuit 314 train. The inductance of the receiver coil 302 and the capacity of the receiving circuit capacitor 308 are coordinated so that a resonant frequency of the receiving resonant circuit 314 (Series or parallel connection of the receiver coil 302 and the receiving circuit capacitor 308 ) substantially equal to the resonant frequency transmitter resonant circuit 64 the loader 20 is. When the reception frequency is tuned to the transmission frequency, the inductive coupling is particularly efficient with respect to that of the device 300 receivable power.

In the in 3 shown embodiment of a battery charging system are both the transmitting coil 246 the loader 220 (which will be described below) as well as the receiving coil 302 designed in the form of Litz wire antennas. Furthermore, a shape of the transmitting coil 297 surrounding housing section of the loading device 220 and the shape of the magnetic field irradiation area 222 bounding wall 224 adapted to a shape of a housing portion of the device 300 which is for making the inductive coupling of the coils 297 and 302 in the magnetic field irradiation room area 222 is introduced. In this way, the Litz wire antenna-shaped receiving coil 302 relatively close to the similarly shaped transmitter coil 297 be brought, whereby an effective inductive coupling and energy transfer is achieved.

Typically form a charging device 20 and a device to be powered by it 300 with a rechargeable battery 326 a battery charging system 10 in which both mechanical parameters, such as the shape of the magnetic field irradiation space region 22 and the shape of this with defining wall 24 to the shape of a housing portion of the device 300 , as well as electrical parameters, such as the reception frequency of the receiving resonant circuit 314 to the transmission frequency of the transmitter resonant circuit 64 , the transmission power to the reception power and the AC power in the charging device 20 to the induced current in the device 300 , are adapted to each other.

After using the 5 to 9 Possibilities of evaluating parameters that can be determined from measuring frequency characteristics and / or their change with respect to a reference frequency characteristic have been described by way of example, will be described below with reference to 2 and 3 Further possibilities of embodiment (embodiments) of a charging device 120 and 220 , respectively, different from the loader 20 from the 1 distinguish, described.

The in the 2 shown second embodiment of a charging device according to the invention 20 is different from the one in the 1 embodiment shown in the embodiment of the AC power and Frequenzsweepsystems including the associated control device. The already on the basis of 1 described functions of the evaluation 82 , the storage device 86 and the output device 88 are in the embodiment of 2 essentially the same, so the evaluation device 182 , the storage device 186 and the output device 188 the charging devices 120 will not be described in detail.

In the in 2 In the embodiment shown, the AC generating and frequency sweeping system includes a power generator 128 with an output terminal 130 which generates an alternating current at a constant frequency and at the output terminal 130 provides a separate AC generator with frequency sweep function (sweep generator) 158 which generates an alternating current with a time-variable frequency, for example having a sawtooth time characteristic of the frequency, and at the sweep generator output 162 provides. The system further includes a switching device 160 which has two inputs and one output and is capable of selectively and switchably switching one or the other input to the output (ie to connect to the output), one input to the output terminal 130 of the power generator 128 and the other entrance with the Sweep generator output 162 of the sweep generator 158 connected is. The system still further includes an amplifier 136 the one over his entrance 138 fed alternating current and between its first and second output 142 and 144 provides a boosted alternating current. The entrance 138 of the amplifier 136 is with the output of the switching device 160 connected, leaving the entrance 138 by means of the switching device 160 optionally and switchable either from the power generator 128 provided alternating current with constant frequency or the sweep generator 158 provided alternating current with a second variable frequency can be supplied.

The system still further includes a transmitter resonant circuit 164 into which the amplified (and with regard to the time dependence of the frequency switchable) alternating current is fed. The structure of the transmitter resonant circuit 164 the loader 120 corresponds to that of the transmitter resonant circuit 64 the loader 20 from the 1 , Due to the switchability, however, the transmitter resonant circuit 164 be operated in different modes. If the switching device 160 the output of the alternator 128 , ie an alternating current with time-constant frequency to the amplifier 136 passes, the transmitter resonant circuit operates 164 to supply energy to an energetic device (in 2 not shown). If the switching device 160 the output of the sweep generator 158 , ie an alternating current with time-variable frequency to the amplifier 136 passes, the transmitter resonant circuit operates 164 in a frequency sweep mode, which allows for object recognition according to the invention and / or foreign body detection by evaluation of a measurement frequency characteristic.

The in the 3 shown third embodiment of a charging device according to the invention 220 is also different from the one in the 1 embodiment shown in the embodiment of the AC power and Frequenzsweepsystems including the associated control device. The already on the basis of 1 described functions of the evaluation 82 , the storage device 86 and the output device 88 are in the embodiment of 3 essentially the same, so the evaluation device 282 , the storage device 286 and the output device 288 the charging devices 220 will not be described in detail.

In the in 2 In the embodiment shown, the alternating current generation and frequency sweeping system comprises a separate part (elements 228 . 236 . 260 . 274 and 246 ) for generating a frequency sweep on a separate transmit coil 246 , which is used for carrying out the object recognition and foreign body recognition according to the invention, and a part (elements 291 . 293 . 297 and 299 ) for the production of an alternating current power and for the transmission of energy, in particular energy with high power, for the supply of a device to be supplied with energy 300 , in particular at a high power, as is required, for example in the case of an electric vehicle for charging its traction battery.

The separate part for generating a frequency sweep includes a power generator 228 with frequency sweep function and with one output terminal 230 which generates an alternating current with a time-variable frequency, for example, having a sawtooth time characteristic of the frequency, and at the output terminal 230 providing an amplifier 236 the one over his entrance 238 fed alternating current and between its first and second output 242 and 244 provides a boosted alternating current and into a transmitter resonant circuit 264 feeds. Here is the entrance 238 of the amplifier 236 with the exit 230 of the power generator 228 connected. The structure of the transmitter resonant circuit 264 the loader 220 corresponds to that of the transmitter resonant circuit 64 the loader 20 from the 1 with the exception of the design of the transmitting coil 264 for the emission of the alternating magnetic field with frequency sweep.

In the in the 3 shown embodiment of the charging device 220 is the transmitter coil 246 formed annular. The transmitter coil surrounds 246 a power transmitting coil 297 which belongs to the part for the generation of a power alternating current and for the transmission of high power energy. Incidentally, the separate part corresponds to the generation of a frequency sweep in the 3 the basis of the 1 described AC and Sweepgeneratorsystem. The transmitting coil 246 serves to generate the time-variable frequency modulated magnetic alternating field, which is required for the inventive object and foreign body detection.

The part for the generation of an alternating current power and for the transmission of energy, in particular energy with high power comprises power generator 291 with a power generator output 292 and for generating an alternating current, in particular a high-power, a power amplifier 293 , that at the power generator output 292 supplied AC power is supplied and for amplifying that of the power generator 291 AC power used to produce an even further amplified AC power with even higher power and between its first and second output 294 and 295 provide. The part for transmitting energy further includes a power transmitter resonant circuit 296 , which is a wire sending coil 297 and a power capacitor 299 includes. The line transmitter coil 297 and the power capacitor 299 are connected in series and the inductance of the coil 297 and the capacitance of the capacitor 299 are chosen so that the power transmitter resonant circuit 296 is tuned to a transmission frequency, the receiving frequency provided for inductive coupling, to be supplied with energy device 300 equivalent. The cable transmitter coil 297 is, for example, according to the well-known and initially mentioned Qi standard of the WPC consortium, as a substantially disc-shaped and helically wound conductor wire shaped stranded wire arrangement 298 educated. The cable transmitter coil 297 serves to send out a magnetic alternating field with constant time frequency and with high energy density or power to the device to be supplied with energy 300 to transmit in a known manner.

In the transmitter resonant circuit 64 . 164 . 264 a loader 20 . 120 . 220 can the capacitor with the transmitter coil 46 . 146 . 246 be connected in a series circuit, as in the 1 to 3 is shown. Alternatively, the capacitor may be connected to the transmitting coil in a parallel circuit (not shown). In both cases, the value of the capacitance of the capacitor 52 and the value of the inductance of the transmitting coil 64 be coordinated so that the transmitter resonant circuit (with series or parallel connection of transmitting coil and capacitor) has a predetermined resonant frequency (transmission frequency), which is the receiving frequency of a receiving resonant circuit of a proposed, to be supplied with energy device 300 is tuned.

LIST OF REFERENCE NUMBERS

10

Battery charging system

12

inductive coupling

20

loader

22

Magnetic radiation room area

24

wall

26

foreign body

28

AC and sweep generator

30

first output terminal

32

second output terminal

34

Generator control input

36

amplifier

38

first entrance

40

second entrance

42

first exit

44

second exit

45

Amplifier control input

46

transmitting coil

47

Litz-wire arrangement

48

first connection

50

second connection

52

capacitor

54

first connection

56

second connection

64

Transmitting resonant circuit

66

Voltage measuring device

68

first connection

70

second connection

72

Voltage measuring signal line

74

Current measurement device

76

first connection

78

second connection

80

Current sensing signal line

82

evaluation

84

control device

86

memory device

88

output device

90

output signal

120

loader

128

Alternator

130

output port

134

Generator control input

136

amplifier

138

entrance

142

first exit

144

second exit

145

Amplifier control input

146

transmitting coil

147

Litz-wire arrangement

148

first connection

150

second connection

152

capacitor

154

first connection

156

second connection

158

Sweep Generator

160

switchover

162

Sweep generator output

163

Sweep control input

164

Transmitting resonant circuit

166

Voltage measuring device

168

first connection

170

second connection

172

Voltage measuring signal line

174

Current measurement device

180

Current sensing signal line

182

evaluation

184

control device

186

memory device

188

output device

190

output signal

220

loader

222

Magnetic radiation room area

224

wall

228

AC and sweep generator

230

output port

234

Generator control input

236

amplifier

238

entrance

242

first exit

244

second exit

245

Amplifier control input

246

transmitting coil

248

first connection

250

second connection

252

capacitor

254

first connection

256

second connection

264

Transmitting resonant circuit

266

Voltage measuring device

268

first connection

270

second connection

272

Voltage measuring signal line

274

Current measurement device

276

first connection

278

second connection

280

Current sensing signal line

282

evaluation

284

control device

286

memory device

288

output device

290

output signal

291

Power Generator

292

Power generator output

293

power amplifier

294

first exit

295

second exit

296

Power transmission resonant circuit

297

Line transmitter coil

298

Litz-wire arrangement

299

power capacitor

300

device to be supplied with energy

302

receiving coil

304

first connection

306

second connection

308

Reception circuit capacitor

310

first connection

312

second connection

314

Receiving resonant circuit

316

rectifier

318

first AC input

320

second AC input

322

first DC voltage output

324

second DC voltage output

326

battery

328

first connection pole

330

second connection pole

400

Frequency characteristic

402

resonant frequency

404

Amplitude at resonance frequency

406

evaluation level

408

first frequency

410

second frequency

500

measuring frequency

502

frequency range

504

Amplitude at measuring frequency

506

Reference frequency response

510

first measuring frequency characteristic

512

second measuring frequency characteristic

520, f _res

Resonant frequency measured value

522, Q

Quality measurement

524

first resonance frequency threshold

526

second resonant frequency threshold

528

first quality threshold

530

second quality threshold

540

Sample 0 (reference measurement)

542

Sample 1

544

Sample 2

546

Sample 3

548

Sample 4

550

Sample 5

552

Sample 6

554

Sample 7

556

Sample 8

600

measuring frequency

602

frequency range

604

Amplitude at measuring frequency

606

Reference frequency response

608

first measuring frequency characteristic

610

second measuring frequency characteristic

612

third measuring frequency characteristic

614

fourth measuring frequency characteristic

616

fifth measurement frequency characteristic

Claims (14)

Loading device ( 20 ) for inductive energy transmission to a device to be supplied with energy ( 300 ) with a rechargeable battery ( 326 ), the loading device ( 20 ) comprising: an AC or AC generator ( 28 ), which is designed to generate an alternating electrical current or an alternating electrical voltage with a voltage in a predetermined frequency range ( 502 . 602 ) time-variable frequency ( 500 . 600 ) and one of the time-variable frequency, to generate predetermined current or voltage amplitude and a transmitting coil ( 46 ) containing transmitter ( 64 ), the transmitting coil ( 46 ), through which an alternating current can be conducted or to which an alternating voltage can be applied and which is designed to generate a magnetic alternating field which is generated under the action of the alternating current or an alternating current driven by the applied alternating voltage whose field strength varies with the time-variable frequency ( 500 . 600 ) varies in a predetermined magnetic field radiation area ( 22 ), characterized by a current and / or a voltage measuring device ( 74 . 66 ), which is designed as a measuring frequency characteristic ( 510 - 512 . 608 - 616 ) a dependence of an amplitude ( 504 . 604 ) one through the transmitting coil ( 46 ) flowing measuring alternating current and / or one at the transmitting coil ( 46 ) applied measuring alternating voltage from the time-variable frequency ( 500 . 600 ), and an evaluation device ( 82 ), which is designed to (a) have a measuring frequency characteristic ( 510 - 512 . 608 - 616 ) with respect to one or more characteristic features selected from the following: (i) a total inductance of the transmitter resonant circuit ( 64 ), (ii) a resonant frequency ( 402 . 520 ) of the transmitter resonant circuit ( 64 ), (iii) a current or voltage amplitude ( 404 ) of the measured alternating current or the measured alternating voltage at the resonance frequency ( 402 ), (iv) a current or voltage amplitude ( 504 . 604 ) of the measured alternating current or the measured alternating voltage at a predetermined frequency range ( 502 . 502 ) contained measuring frequency ( 500 . 600 ), (v) one of the measuring frequency characteristic ( 510 - 512 . 608 - 616 ) certain quality ( 522 ) of the transmitter resonant circuit, (vi) a parameterizable form of a measurement-frequency characteristic ( 510 - 512 . 608 - 616 ) in the predetermined frequency range ( 502 . 602 ) and (vii) a correlation of the measurement frequency characteristic ( 510 - 512 . 608 - 616 ) with a reference frequency characteristic ( 506 . 606 ), which has a dependence of a through the transmitting coil ( 46 ) reference reference alternating current and / or a reference coil voltage applied to the transmitting coil of the time-variable frequency, wherein the reference frequency characteristic ( 506 . 606 ) has been measured under a condition that the magnetic field irradiation space area ( 22 ) is substantially free of an object, and (b) based on an evaluation of at least one of the characteristic features (i) to (vii) for the presence of a metal-containing object ( 26 ) in the magnetic field irradiation space region ( 22 ), the evaluation device ( 82 ) is adapted to detect and / or discriminate whether in the magnetic field irradiation space region ( 22 ) a device to be supplied with energy ( 300 ) of a predetermined type, for example a mobile telephone, a smartphone or an audio player, such as an MP3 player, or another type of metal-containing foreign body ( 26 ), such as a coin, a metal foil, a metal ring and / or a paper clip. Device according to claim 1, characterized in that the evaluation device ( 82 ) is adapted, based on an evaluation of the change in the resonant frequency ( 402 . 520 ) and / or the quality ( 522 ) and / or to distinguish whether in the magnetic field radiation area ( 22 ) a device to be supplied with energy ( 300 ) of a predetermined type or a different metal-containing foreign body ( 26 ) is available. Device according to claim 2, characterized in that in a memory device ( 86 ) a first and second, predetermined resonance frequency threshold ( 524 . 526 ) and a first and second, predetermined quality threshold value ( 528 . 530 ), the second resonant frequency threshold ( 526 ) greater than the first resonant frequency threshold ( 524 ) and the second quality threshold ( 530 ) greater than the first quality threshold ( 528 ). Device according to claim 3, characterized in that the evaluation device ( 82 ) is designed, when the resonance frequency ( 402 . 520 ) greater than the second resonant frequency threshold ( 526 ) and the goodness ( 522 ) smaller than the first quality threshold ( 528 ) is to detect that in the magnetic field irradiation space area ( 22 ) a metal-containing foreign body ( 26 ) to be supplied by an energy-supplied facility ( 300 ) is different from one of the predetermined types. Device according to claim 3, characterized in that the evaluation device ( 82 ) is designed, when the resonance frequency ( 402 . 520 ) larger than the first ( 524 ) and smaller than the second ( 526 ) Resonant frequency threshold and the quality ( 522 ) greater than the second quality threshold ( 530 ) is to detect that in the magnetic field irradiation space area ( 22 ) a device to be supplied with energy ( 300 ) of one of the predetermined types. Device according to one of claims 1 to 5, further characterized by an output device ( 88 ) operatively connected to the evaluation device ( 82 ) and is designed for this purpose if the evaluation device ( 82 ) has detected that in the magnetic field irradiation space region ( 22 ) a metal-containing foreign body ( 26 ) to be supplied by an energy-supplied facility ( 300 ) is different from one of the predetermined types, an indication signal ( 90 ) indicative of this detected circumstance. Device according to one of claims 1 to 6, characterized in that the magnetic field irradiation space area ( 22 ) at least in sections by means of a mechanical wall ( 24 ), in particular the wall ( 24 ) has a shape of a spherical section, an ellipsoidal section, a cone, a shell or a planar surface. Device according to one of claims 1 to 7, further characterized by a capacitor ( 52 ) having a capacitance connected to the transmitting coil ( 46 ) is connected in a series circuit or a parallel circuit and wherein the value of the capacitance and the value of the inductance are coordinated with each other so that this series or parallel circuit has a predetermined resonant frequency. Energy-supplied device ( 300 ) with a rechargeable battery ( 326 ) adapted for use in inductive coupling with a charging device ( 20 ) according to one of claims 1 to 9. Device according to claim 9, characterized in that it is a mobile phone, a smartphone or an audio player, such as an MP3 player. Device according to claim 9, characterized in that it is an electric vehicle, the rechargeable battery ( 326 ) is a driving battery of the electric vehicle. Device according to one of Claims 9 to 11, characterized by a rectifier ( 316 ) having a first and second AC input ( 318 . 320 ) and a first and second DC output ( 322 . 324 ), and a receiving coil ( 302 ) connected in series between the first and second AC input ( 318 . 320 ), wherein the rechargeable battery ( 326 ) in series between the first and second DC output ( 322 . 324 ) is switchable. Battery charging system ( 10 ), comprising a charging device ( 20 ) according to one of claims 1 to 8 and a device to be supplied with energy ( 300 ) according to any one of claims 10 to 13, wherein the loading device ( 20 ) for inductive transmission of energy to the device ( 300 ), in particular for charging its battery ( 326 ), is trained. Battery charging system according to claim 13, characterized in that the charging device ( 20 ) according to claim 8 and that the device to be supplied with energy ( 300 ) a receiving circuit capacitor ( 308 ) connected to the receiving coil ( 302 ) is connected in series or in parallel, wherein an inductance of the receiving coil ( 302 ) and a capacity of the receiving circuit capacitor ( 308 ) are matched to one another such that a resonance frequency of the series or parallel connection of the receiving coil ( 302 ) and the receiving circuit capacitor ( 308 ) substantially equal to the resonant frequency of the series or parallel connection of the transmitting coil ( 46 ) and the capacitor ( 52 ) of the charging device ( 20 ).

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