SE1550340A1

SE1550340A1 - A testing device for wireless power transfer, and an associated method

Info

Publication number: SE1550340A1
Application number: SE1550340A
Authority: SE
Inventors: Magnus Wikstrand
Original assignee: Nok9 Ab
Priority date: 2015-03-23
Filing date: 2015-03-23
Publication date: 2016-06-21
Also published as: TWI674725B; EP3073609A1; EP3073609B1; US9739668B2; KR101771669B1; JP2016180754A; JP6571738B2; TW201637321A; CN105987763B; US20170314998A1; KR20170098779A; KR20160113997A; CN105987763A; JP2018040808A; JP6235642B2; KR102316454B1; US20160282192A1; SE538428C2; US10060801B2

Description

Typically, a base station has a ?at surface, on top of which a user can place one or more mobile devices so as to enjoy wireless battery charging or operational power supply for the mobile device(s) placed on the base station.

During operation, heat will be generated by magnetic induction in the secondary coil of the power receiver, i.e. in the mobile device. Moreover, the power transmitter in the base station will generate heat that will be conveyed from the base station to the mobile device. If the therrnal exposure for the mobile device becomes excessive, several undesired effects may arise. For instance, vital components may be damaged in the mobile device, such as for instance a lithium ion battery or electronic circuitry in a smartphone. At severe overheating, objects in the vicinity of the mobile device may be damaged and even cause a fire or toxic smoke hazard. Furthermore, the duration of the charging period may be prolonged, since protective circuitry in the mobile device may intervene to reduce or even suspend the charging power until the temperature has been reduced again. Also, the intended user will become generally suspicious and assume a somewhat negative position with respect to the mobile device (or the base station) if the mobile device is too hot when picked up from the surface of the base station.

There is therefore a need among different interest groups to test, measure, evaluate, emulate or otherwise assess the therrnal exposure of a mobile device when being subj ected to wireless power transfer from a wireless power transmitter. Such interest groups may for instance involve any of the following: developers, manu- facturers or suppliers of mobile devices; developers, manufacturers or suppliers of wireless power transmitter devices; test or compliance entities in the ?eld of wireless power transfer; and test or compliance entities in the field of consumer product safety.

Summary It is an object of the invention to offer improvements in the technical ?eld of wireless power transfer.

One aspect of the present invention is a testing device for use with a wireless power transmitter device having a wireless power transmitter coil. The testing device comprises a housing. The housing has a bottom side adapted for placement on a surface of the wireless power transmitter device, and a top side opposite to the bottom side.

The testing device also comprises a wireless power receiver coil provided in the housing, therrno sensory means, and an interface to provide measurement data from the therrno sensory means. The therrno sensory means comprises a first temperature sensor adapted to measure a temperature at a first position inside the housing. The thermo sensory means also comprises a second temperature sensor adapted to measure a temperature at a second position external to the housing.

Advantageously, the housing has a lower housing part comprising said bottom side, and an upper housing part comprising said top side. The upper housing part is preferably made of a material having heat dissipation properties similar to a typical mobile device, such as a smartphone, that the wireless power transmitter device is designed for use with. Hence, the upper housing part advantageously comprises at least one of aluminium and glass.

Preferably, the first temperature sensor is positioned in or at a socket which protrudes downwardly from an inner surface of the upper housing part. The socket may be an integral part of and made of the same material as the upper housing part. The socket preferably has a surface with an area dimensioned to match a horizontal extension of a surface of a ferrite layer for the wireless power receiver coil. This allows the socket to serve as a mount for the ferrite layer.

Advantageously, a heat transferring layer is provided between the surface of the socket and the surface of the ferrite layer. The heat transferring layer is preferably made of a resilient, adhesive and heat conductive material, and is adapted to establish optimal transfer of heat generated by the wireless power receiver coil to the upper housing part.

The testing device may comprise a cable for connection to a host device. The cable may be comprised in or connected to the interface of the testing device.

Bene?cially, the second temperature sensor may be positioned on the cable at a distance from the housing. The first temperature sensor may thus be adapted to provide measurement data indicative of a temperature related to heat generated internally in the testing device by the wireless power receiver coil, whereas the second temperature sensor may be adapted to provide measurement data indicative of a temperature related to ambient air around the testing device.

Optionally, the therrno sensory means of the testing device further comprises a third temperature sensor being adapted to measure a temperature at a third position, wherein the third position is inside the housing and different from the ?rst position.

Advantageously, the third temperature sensor is positioned between the wireless power receiver coil and the bottom side of the housing, wherein the third temperature sensor may be adapted to provide measurement data indicative of a temperature related to heat generated by the wireless power transmitter coil of the wireless power transmitter device.

As will be apparent from the detailed description of embodiments of this invention, the testing device may be beneficially used to test, measure, evaluate, emulate or otherwise assess the thermal exposure of a mobile device when being subjected to wireless power transfer from a wireless power transmitter device having a wireless power transmitter coil, such as a wireless charger for a smartphone.

Another aspect of the present invention is a method of emulating the thermal exposure of a mobile device when being subjected to wireless power transfer from a wireless power transmitter device having a wireless power transmitter coil. According to the method, a testing device is provided which has a wireless power receiver coil matching the wireless power transmitter coil, and which has a housing with thennal absorption and dissipation properties matching a mobile device to be emulated.

According to this method, the wireless power transmitter device is operated during an operational time to generate wireless power to the testing device. A ?rst temperature is measured at a first position inside the housing of the testing device during the operational time. Moreover, a second temperature is measured at a second position external to the housing of the testing device during the operational time.

Measurement data from the measuring of the first temperature and the second temperature during the operational time is then provided to a processing means, which may be part of a host device.

Advantageously, the processing means records the measurement data and evaluates whether the measurement data indicates a long-terrn deviation between the first temperature and the second temperature in excess of a threshold value during or at the end of the operational time. If so, the processing means generates an alarrn signal.

Just as for the first aspect of the invention, the ?rst position may advantageously be between the wireless power receiver coil and a top side of the housing of the testing device, wherein the measuring of the first temperature will be indicative of a temperature related to heat generated intemally in the testing device by the wireless power receiver coil. Correspondingly, the second position may advantageously be at a distance from the housing of the testing device, wherein the measuring of the second temperature will be indicative of a temperature related to ambient air around the testing device.

In one embodiment, the therrnal exposure testing is refined by measuring also a third temperature at a third position inside the housing of the testing device during the operational time. The third position will be different from the ?rst position, and the measurement data provided to the processing means will include also the measuring of the third temperature.

Just as for the first aspect of the invention, the third position may advantageously be between the wireless power receiver coil and the bottom side of the housing of the testing device, and the measuring of the third temperature will be indicative of a temperature related to heat generated by the wireless power transmitter coil of the wireless power transmitter device.

Embodiments of the invention are defined by the appended dependent claims and are further explained in the detailed description section as well as on the drawings.

It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps, or components, but does not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof All terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly de?ned otherwise herein. All references to "a/an/the [element, device, component, means, step, etc]" are to be interpreted openly as referring to at least one instance of the element, device, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

Directions and orientations is three-dimensional space for the testing device as described herein are generally expressed with respect to a horizontal orientation for the testing device, corresponding to the testing device lying on a horizontal surface.

Brief Description of the Drawings Objects, features and advantages of embodiments of the invention will appear from the following detailed description, reference being made to the accompanying drawings.

Fig 1 is a schematic block diagram of a wireless power transmitter device for wireless power transfer to a mobile device.

Fig 2 is a schematic block diagram of a testing device having therrno sensory means for use with a wireless power transmitter device, and a host device for processing of measurement data provided by the testing device.

Fig 3 is an isometric view of a testing device according to one embodiment, placed on a surface of a wireless power transmitter device.

Figs 4 and 5 are isometric exploded Views of a testing device according to one embodiment.

Figs 6 and 7 are isometric exploded views of a testing device according to another embodiment.

Fig 8 is a graph illustrating exemplary measurement data obtainable by the therrno sensory means of the testing device.

Fig 9 is a ?owchart diagram of a method of emulating the therrnal exposure of a mobile device when being subj ected to wireless power transfer from a wireless power transmitter device.

Detailed Description Embodiments of the invention will now be described with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The terrnino lo gy used in the detailed description of the particular embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention.

In the drawings, like numbers refer to like elements.

Fig 1 illustrates a wireless power transmitter device 20 for wireless power transfer to a mobile device 10. The mobile device may, for instance, be a mobile terminal (e.g. smartphone) 10a, tablet computer l0b (e.g. surfpad), laptop computer 10c, camera, audio player, rechargeable toothbrush, wireless headset, or another kind of consumer product or appliance.

The wireless power transfer will be described as being compliant with the Qi standard by the Wireless Power Consortium; hence, the wireless power transmitter device 20 is a base station in the Qi terrninology. However, as already mentioned, the invention is generally applicable also to other wireless power transfer standards or approaches, including but not limited to the ones mentioned in the Background section.

The wireless power transmitter device 20 comprises a wireless power transmitter 22 having a wireless power transmitter coil 24. Correspondingly, the mobile device 10 comprises a wireless power receiver 12 having a wireless power receiver coil 14. In operation, the wireless power transmitter device 20 will transfer power wirelessly to the mobile device 10 by way of magnetic induction 18 via the wireless power transmitter coil 24 and wireless power receiver coil 14.

The power received by the wireless power receiver coil 14 will drive a load 16 in the mobile device 10. Typically, the load 16 may be a rechargeable battery, such as a lithium ion battery; hence, the Wireless power transmitter device 20 will act as a wireless power charger for the mobile device 10. In another scenario, the load 16 may be electronic circuitry in the mobile device, wherein the wireless power transmitter device 20 will act as a wireless power supply for the mobile device 10.

As explained in the Background section, during operation, the wireless power transmitter 22 and coil 24 will generate heat that will be conveyed from the wireless power transmitter device 20 to the mobile device 10. Moreover, heat will be generated by magnetic induction in the wireless power receiver coil 14 in the mobile device 10. If the heat exposure for the mobile device 10 becomes excessive, vital components may be damaged in the mobile device, such as for instance a rechargeable battery or electronic circuitry. Also, excessive heat exposure for the mobile device may increase the risk for fire or smoke generation.

To this end, a testing device 30 has been provided, embodiments of which are illustrated in Figs 2-7. There is also provided an associated method of emulating the thermal exposure of a mobile device when being subjected to wireless power transfer from a wireless power transmitter device. This method is illustrated in Fig 9.

Fig 2 is a schematic block diagram which shows a testing device 30 for use with a wireless power transmitter device 20. The wireless power transmitter device 20 has a wireless power transmitter 22 and a wireless power transmitter coil 24, and may be identical to the wireless power transmitter device 20 in Fig 1. As will be described in more detail below, the testing device 30 has a wireless power receiver 32 with a wireless power receiver coil 34 which matches the wireless power receiver coil of a mobile device (or type of mobile device) to be emulated. Moreover, the testing device has a housing with therrnal absorption and dissipation properties matching the mobile device (or type of mobile device) to be emulated.

In operation, the wireless power transmitter device 20 will transfer power wirelessly to the testing device 30 by way of magnetic induction 18 via the wireless power transmitter coil 24 and wireless power receiver coil 34 during an operational time OT of a test session. As a result, heat will be generated as explained above for Fig 1.

To measure the thermal exposure of the testing device 30 caused by the wireless power transfer from the wireless power transmitter device 20, thermal sensory means 31 are provided in the testing device 30. The therrnal sensory means 31, which will be described in more detail below, will provide measurement data via an interface 33 to a host device 40, as seen at 35 in Fig 2.

The host device 40 has an interface 41 for receiving the measurement data obtained by the therrnal sensory means 31 in the testing device 30. The interfaces 33 and 41 may be of any suitable type, including simple wiring, a serial interface such as USB, a wireless interface such as Bluetooth of WiFi, etc.

The host device 40 also has processing means 42 for processing the measure- ment data received from the testing device 30. The processing means 42 may comprise a programmable device, such as a microcontroller, central processing unit (CPU), digital signal processor (DSP) or field-programmable gate array (FPGA) with appropriate software and/or firmware, and/or dedicated hardware such as an application-speci?c integrate circuit (ASIC).

Furthermore, the host device 40 has reporting means 43 for communicating or presenting the measurement processing results obtained by the processing means 42.

This may involve presentation of graphical information on a local user interface (e. g. display) of the host device 40, generating of visual and/or audible alarms, or communication of information to an external device, as seen at 45.

The processing means 42 may also control and/or drive the wireless power transmitter device 20 for the purpose of the test session, as seen at 44.

A suitable load 36 may be provided to handle excess power received by the wireless power receiver coil 34 in the testing device 30. For instance, a suitably dimensioned resistor may be used.

Embodiments of the testing device 30 will now be described with reference to Figs 3-7. Figs 4-5 illustrate a first embodiment, whereas Figs 6-7 illustrate a second embodiment which is identical to the first embodiment except for the provision of an additional element of the therrnal sensory means 31. Fig 3 is common to both embodi- ments. Other embodiments than the illustrated ones are possible within the scope of the invention.

As seen particularly in Fig 3, the testing device 30 has essentially the shape of a thin box with rounded edges and comers. The disclosed embodiment serves to emulate a mobile device in the form of a smartphone; hence the testing device 30 has the familiar smartphone shape. The testing device 30 has a sandwich design with the footprint dimensions 130 mm x 70 mm in the disclosed embodiment. The sandwich design includes a housing 50 having a lower housing part 51, an interrnediate housing part 70 and an upper housing part 52.

The lower housing part 51 has a bottom side 53 adapted for placement on a surface 25 of the wireless power transmitter device 20. The upper housing part 52 has a top side 54 opposite to the bottom side 53. The lower housing part 51 is made of plastic or another material suitable for admitting inductive coupling 18 between the wireless power transmitter coil 24 of the wireless power transmitter device 20 and the wireless power receiver coil 34 of the wireless power receiver 32.

The interrnediate housing part 70 is made of plastic or another material suitable for providing sufficient stability to the sandwich design.

The upper housing part 52 is made of a material having heat dissipation properties similar to a typical mobile device that the wireless power transmitter device is designed for use with. Advantageously, the upper housing part 52 may comprise aluminium or another material with similar heat dissipation properties, such as glass, or a combination thereof.

In the disclo sed embodiment of Fig 3, the wireless power transmitter device 20 has a cable 44a, which may be connected to the host device 40, as indicated at 44 in Fig 2. The testing device 30 has a cable 35a which may be part of the interface 33 to the host device 40, as indicated at 35 in Fig 2.

Reference is now made to the exploded isometric views in Figs 4 and 5, illustrating the first embodiment of the testing device 30 as viewed from one of its longitudinal sides and one of its lateral sides, respectively. The interrnediate housing part 70 has been removed from the views in Figs 4 and 5 (and in Figs 6 and 7) for enhanced clarity.

The testing device 30 has a sandwich design also intemally, as appears from Figs 4 and 5. The wireless power receiver coil 34 is provided in the housing 50 as one of the layers of the sandwich design. Immediately above the wireless power receiver coil 34, a ferrite layer 58 for the wireless power receiver coil 34 is provided.

The interface 33 is not shown as such in Figs 4 and 5, but it may for instance be implemented as a small printed circuit board located within the housing 50 near an opening for the cable 35a, the opening being formed by semicircular cutouts 351,, 351 in the upper and lower housing parts 52, 51.

A first temperature sensor 55, being part of the therrno sensory means 31, is provided above the wireless power receiver coil 34. The first temperature sensor 55 is adapted to measure a temperature at a first position inside the housing 50. More specifically, the ?rst temperature sensor 55 is positioned between the wireless power receiver coil 34 and the top side 54 of the housing 50. Even more specifically, the first temperature sensor 55 is positioned in or at a socket 59 (a.k.a. base or pedestal) which protrudes downwardly from an inner surface of the upper housing part 52 of the housing 50.

In the illustrated embodiment, the socket 59 is an integral part of the upper housing part 52 and is therefore made of the same material as the upper housing part 52, i.e. preferably aluminium or a material with similar heat dissipation properties, such as glass. The upper housing part 52 with its socket 59 serves as a receiver or accumulator of heat generated by the wireless power receiver coil 34. The dimensions, mass and material of the upper housing part 52 with its socket 59 are hence advantageously chosen so that their combined heat dissipation properties will resemble those of a typical mobile device, such as a smartphone, for which the wireless power transmitter device 20 is designed for use with. This will enable an accurate emulation of the therrnal exposure of such a typical mobile device when being subjected to wireless power transfer from. e. g. charged by, the wireless power transmitter device 20.

The socket 59 also serves as mount for the ferrite layer 58 in the illustrated embodiment. To this end, the socket 59 has a surface 595 (facing downwards in the drawings) having an area which is dimensioned to match the horizontal extension of the surface 585 of the ferrite layer 58 for the wireless power receiver coil 34, as can be seen in Figs 4-7. “Matching” means, in this context, that the area of the surface 595 of the socket 59 is suf?ciently large relative to the surface 585 of the ferrite layer 58, so that the socket 59 may serve as a mount for the ferrite layer 58. Hence, “matching” does not require that the areas are equally large; as can be seen in Figs 4-7, the surface 595 of the socket 59 is somewhat smaller than the surface 585 of the ferrite layer 58 in these embodiments.

Advantageously, a heat transferring layer 60 is provided between the surface 595 of the socket 59 and the surface 585 of the ferrite layer 58. The heat transferring layer 60 will serve to establish optimal transfer of heat generated by the wireless power receiver coil 34 to the upper housing part 52 with its socket 59 and avoid any undesired iso lation effects which might otherwise appear had the ferrite layer 58 abutted directly against the socket 59. Such undesired isolation effects might otherwise jeopardize the accuracy of the resemblance of the combined heat dissipation properties of the upper housing part 52 with its socket 59 with respect to a typical mobile device, since the amount of heat actually received by the upper housing part 52 with its socket 59 would be less, to an unknown extent, than the heat generated by the wireless power receiver coil 34. ll The heat transferring layer 60 is preferably made of a resilient and adhesive material with good heat conducting capability, such as, for instance, silicon grease, therrnal paste or therrnal tape. The adhesive properties of the material may be inherent or altematively provided by an additional adhesive. The resiliency and adhesiveness, or stickiness, of the material will facilitate the assembly of the testing device 30 by securing the heat transferring layer 60 in a correctly aligned position between and in contact with the surface 595 of the socket 59 as well as the surface 585 of the ferrite layer 58.

Advantageously, the first temperature sensor 55 is mounted in a bore or island in the socket 59, or in a channel or groove in the surface 595 of the socket 59. This keeps the surface 595 of the socket 59 even and uninterrupted and therefore enables full contact with the heat transferring layer 60 and, as a result, optimal transfer of heat generated by the wireless power receiver coil 34 to the upper housing part 52. Also, this location of the first temperature sensor 55 is advantageous also because it is well separated and magnetically isolated from the wireless power receiver coil 34; hence, in?uence from magnetic fields generated from induction in the wireless power receiver coi134 can be avoided.

In altemative embodiments, the first temperature sensor 55 may, for instance, be attached to the surface 595, or to a lateral edge 595 of the socket 59, by a suitable fastening means.

The therrno sensory means 31 also comprises a second temperature sensor 56.

The second temperature sensor 56 is adapted to measure a temperature at a second position extemal to the housing 50. Hence, unlike the first temperature sensor 55, the second temperature sensor 56 is not located within the housing 50 but outside of it. The second temperature sensor 56 serves to measure an ambient temperature around the testing device 30. More speci?cally, in the disclosed embodiments, the second temperature sensor 56 is positioned on the cable 35a at a certain distance 61 from the housing 50. This is seen in Fig 3. The distance is sufficient to prevent noticeable in?uence on the ambient temperature measurement from heat generated by the wireless power transmitter device 20 or the testing device 30. In some embodiments, a sufficient distance may be at least 150-200 mm from the housing 50.

In the disclosed embodiments, the first and second temperature sensors 55, 56 are thermocouples, such as thermocouples type K which are manufactured by Omega Engineering Limited, One Omega Drive, River Bend Technology Centre, Irlam, Manchester, M44 5BD, United Kingdom. The therinocouples generate small sensor 12 output voltage values which are converted by an associated converter unit into a calibrated temperature value in °C. The converter unit may, for instance, be comprised in the interface 33 or in the host device 40. In other embodiments, other types of temperature sensors may be used, such as for instance therrnistors, resistance therrnometers or silicon bandgap temperature sensors.

The particulars, functions and purposes of the first temperature sensor 55 and the second temperature sensor 56 will now be described.

As seen in Figs 4-5, the first temperature sensor 55 is positioned inside the housing 50 near or at its top side 54. The ?rst temperature sensor 55 is adapted to provide measurement data indicative of a temperature related to heat generated internally in the testing device 30, i.e. by the magnetic induction in the wireless power receiver coil 34. This temperature will also be related to heat dissipated at the top side 54 of the housing 50 (and to some extent also to heat generated by the wireless power transmitter coil of the wireless power transmitter device 20). As a result, therefore, the first temperature sensor 55 will serve to assess the therrnal environment which the internal elements of the emulated mobile device will be exposed to, as it is experienced by the testing device 30 during the operational time OT of the test session. The second temperature sensor 56, on the other hand, is positioned extemal to the housing 50 and is adapted to provide measurement data indicative of a temperature related to ambient air around the testing device 30. This will serve as a reference level when assessing the therrnal exposure of the intemal elements of the emulated mobile device.

The duration OT of the test session may be set to an appropriate maximum value which re?ects a typical duration of a wireless power transfer session for the emulated mobile device, for instance 60 minutes when the emulated mobile device is a mobile terminal and the wireless power transmitter device 20 is a wireless power charger, or for instance 90 minutes, or more generally in time magnitudes between 10] minutes and 103 minutes, without limitation. In one embodiment, the duration OT of the wireless power transfer session may be selected or set in view of a desired or obtained temperature stabilization as indicated by the measurement data provided by the first (and/or third temperature sensor(s) 55 (55°). A criterion for temperature stabilization may then for instance be a deviation which is less than a threshold value, such as 1 °C, between two or more subsequent temperature readings from the first (or third) temperature sensor 55 (55”).

Exemplary graphs resulting from temperature measurements by the first and second temperature sensors 55, 56 are found in Fig 8. The upper graph 81 represents the 13 measurement data obtained from the first temperature sensor 55 and approaches an end temperature at about 36 °C after an operational time OT = 5000 seconds. The lower graph 82 represents the measurement data obtained from the second temperature sensor 56 and ripples around an ambient air temperature at about 25 °C throughout the operational time OT = 5000 seconds.

In an altemative embodiment which is seen in Figs 6-7, the therrno sensory means 31 further comprises a third temperature sensor 55” which is adapted to measure a temperature at a third position, Except for this, the altemative embodiment in Figs 6-7 may be identical to the embodiment in Figs 4-5. The third position is inside the housing 50 and different from the first position. In the disclosed embodiment of Figs 6-7, the third temperature sensor 55” is positioned between the wireless power receiver coil 34 and the bottom side 53 of the housing 50.

The third temperature sensor 55” is adapted to provide measurement data indicative of a temperature related to heat conveyed from the wireless power transmitter device 20 into the testing device 30. As a result, therefore, the third temperature sensor 55” may serve to assess the thermal environment at the bottom of the emulated mobile device, i.e. nearest the wireless power transmitter device 20, as it is experienced by the testing device 30 during the operational time OT of the test session.

The third temperature sensor 55 ” may be more susceptive of in?uence from magnetic fields generated by induction in the wireless power receiver coil 34 than the first temperature sensor 55, because of its location within the reach of the winding of the wireless power receiver coil 34. In another embodiment, therefore, a more distal (non-central) location of the third temperature sensor 55 ” in the lower housing part 51 may be chosen. An altemative approach is described below with reference to step 140 in Fig 9.

The aggregated measurement data provided by the first and second temperature sensors 55, 56, and the third temperature sensor 5 5” if applicable, will allow the processing means 42 to make various analyses of the (emulated) thermal exposure of a mobile device when being subjected to wireless power transfer from a wireless power transmitter device. The results of such analyses may, for instance, be beneficially used by any or all of the following interest groups: 0 Developers, manufacturers or suppliers of mobile devices, 0 Developers, manufacturers or suppliers of wireless power transmitter devices, 0 Test or compliance entities in the field of wireless power transfer, 14 0 Test or compliance entities in the field of consumer product safety.

Fig 9 is a ?owchart diagram of a method of emulating the thermal exposure of a mobile device when being subjected to wireless power transfer from a wireless power transmitter device 20 having a wireless power transmitter coil 24. The method involves the following.

In a first step 110, a testing device is provided which has a wireless power receiver coil matching the wireless power transmitter coil 24 and which has a housing with therinal absorption and dissipation properties matching a mobile device to be emulated. The testing device may advantageously be the testing device 30 as described above for Figs 2-8.

In a second step 120, the wireless power transmitter device 20 is operated during an operational time OT to generate wireless power to the testing device 30. ln a third step 130, a first temperature T1 is measured at a first position in the testing device 30 during the operational time OT.

In a fouith step 135 a second temperature T; is measured at a second position extemal to the testing device 30 during the operational time OT.

In a fifth step 140, which is optional and relates to the embodiment shown in Figs 6 and 7, a third temperature T; is measured at a third position in the testing device during the operational time OT. To avoid or reduce potential in?uence on the third temperature sensor 55” from magnetic fields generated by induction in the wireless power receiver coil 34, the wireless power transmitter coil 24 in the wireless power transmitter device 20 may be momentarily suspended for a short period of time when the third temperature T; is measured.

The measurements in step 130 (and 140, if applicable) will be repeated at suitable intervals during the operational time OT of the test session, such as for instance every x seconds or y minutes. The measurement in step 135 may be repeated at the same intervals, or altematively at longer intervals, since the temperature of ambient air could be expected to remain fairly constant during the operational time OT of the test session. In some embodiments, the measurement in step 135 is only made once (e.g. at the end of the operational time OT of the test session), twice (e. g. at the beginning and the end of the operational time OT of the test session), or three times (e.g. at the beginning, in the middle and at the end of the operational time OT of the test session).

In a step 150, measurement data is provided from the measuring of the first temperature T1 and the second temperature Tg (and optionally the third temperature Tg) during the operational time OT to a processing means, for instance the processing means 42 in the host device 40 in Fig 2.

Advantageously, the method also involves a step 160 where the processing means 42 records the measurement data received from the testing device 30, for instance by storing it in a suitable memory. Moreover, the method advantageously involves a step 170 where the processing means 42 evaluates whether the measurement data indicates a long-terrn deviation between the first temperature T1 and the second temperature T; which exceeds a threshold value during or at the end of the operational time OT of the test session. In the diagram shown in Fig 8, such a deviation will be the distance (in °C) between the ?rst and second graphs 81 and 82 for a given period of time during or, typically, at the end of the operational time OT of the test session. The threshold value may be set to an appropriate value, such as for instance 15 °C, or more generally 10-20 °C (without limitation).

If it has been found in step 170 that the intemal temperature T1 in the testing device 30 as measured by the first temperature sensor 55 exceeds the ambient temperature T; as measured by the second temperature sensor 56 plus the threshold value during a certain time period (e.g. a certain number of measurement samples, or a certain number of seconds), the processing means 42 will conclude in a step 175 that the testing device 30 has been exposed to an excess temperature. As a result, the processing means 42 may generate an alarm signal in a step 180. The alarm signal may be part of the information produced at 45 by the reporting means 43 in Fig 2, or a separate signal triggering for instance a visual and/or audible alarm, or a control signal communicated to an extemal device as an alert of the excess temperature situation.

The method described above for Fig 9 may have any or all of the same or functionally corresponding features as the testing device 30 described above for Figs 2- 8. For instance, the first position is preferably between the wireless power receiver coil 34 and a top side 54 of the housing 50 of the testing device 30, and the measuring of the frst temperature T1 is indicative of a temperature related to heat generated intemally in the testing device 30 by the wireless power receiver coil 34.

Correspondingly, the second position is preferably at a distance 61 from the housing 50 of the testing device 30, and the measuring of the second temperature T; is indicative of a temperature related to ambient air around the testing device 30.

The third position, if applicable, is preferably between the wireless power receiver coil 34 and the bottom side 53 of the housing 50 of the testing device 30, and the measuring of the third temperature T; is indicative of a temperature related to heat 16 generated by the Wireless power transniitter coil 24 of the Wireless power transmitter device 20.

The invention has been described above in detail With reference to enibodinients thereof. However, as is readily understood by those skilled in the art, other embodiments are equally possible Within the scope of the present invention, as defined by the appended clairns.

Claims

1 SE 1550340-2 PATE NTKRAV

1. Testanordning (30) for anvandning med en sandaranordning (20) for tradlos kraft vilken har en sandarspole (24) for tradlos kraft, varvid testanordningen innefattar: ett holje (50), varvid holjet har en undersida (53) anpassad att placeras pa en yta (25) pa sandaranordningen (20) for tradlos kraft, och en ovansida (54) motsatt undersidan (53); en mottagarspole (34) kir tradlos kraft, vilken är anordnad i holjet; termosensoriska organ (31); och ett granssnitt (33) for aft tillhandahalla matdata fran de termosensoriska organen (31), dar de termosensoriska organen (31) innefattar: en forsta temperatursensor (55) som är anpassad att mata en temperatur vid en forsta position inuti holjet (50); och en andra temperatursensor (56) som är anpassad att mata en temperatur vid en andra position utanfor holjet (50).

2. Testanordningen enligt krav 1, dar den forsta temperatursensorn (55) är placerad mellan mottagarspolen (34) for tradlos kraft och ovansidan (54) pa holjet (50).

3. Testanordningen enligt krav 1 eller 2, varvid holjet (50) har en nedre del (51) av holjet vilken innefattar namnda undersida (53), och en ovre del (52) av holjet vilken innefattar namnda ovansida (54), dar den ovre delen (52) av hOljet är gjord av eft material vilket har varmeavgivningsegenskaper som liknar en typisk mobilanordning (10) vilken sandaranordningen (20) for tradlos kraft är konstruerad att anvandas med.

4. Testanordningen enligt krav 3, dar den ovre delen (52) av holjet innefattar atminstone endera av aluminium och glas.

5. Testanordningen enligt krav 3 eller 4, dar den typiska mobilanordningen (10) är en smarttelefon. 2

6. Testanordningen enligt nagot av krav 3-5, vidare innefattande en sockel (59) vilken skjuter ut ned5t fr5n en inre yta (59s) p5 den ovre delen (52) av holjet, dar den fOrsta temperatursensorn (55) är placerad i eller vid namnda sockel (59).

7. Testanordningen enligt krav 6, dar sockeln (59) är en integrerad del av och gjord av samma material som den ovre delen (52) av holjet, varvid sockeln (59) har en yta (59s) med en area som är dimensionerad att overensstamma med en horisontell utstrackning hos en yta (58s) p5 ett ferritskikt (58) for mottagarspolen (34) for tr5dlos kraft, varvid sockeln (59) fungerar som en montering for ferritskiktet (58).

8. Testanordningen enligt krav 7, vidare innefattande ett varmeoverforingsskikt (60) mellan ytan (59s) p5 sockeln (59) och ytan (58s) p5 ferritskiktet (58).

9. Testanordningen enligt krav 8, dar varmeoverforingsskiktet (60) är av ett elastiskt, vidhaftande och varmeledande material, samt är anpassat att astadkomma optimal overforing av varme som alstras av mottagarspolen (34) for tradlos kraft till den ovre delen (52) av holjet.

10. Testanordningen enligt nagot foregaende krav, vidare innefattande en kabel (35a) for anslutning till en vardanordning (40), varvid kabeln (35a) är innefattad i eller ansluten till namnda granssnitt (33), dar den andra temperatursensorn (56) är placerad pa namnda kabel (35a) pa ett avstand (61) fr5 n namnda ht.* (40).

11. Testanordningen enligt nagot foregaende krav, dar den forsta temperatursensorn (55) är anpassad att tillhandahalla matdata som indikerar en temperatur forknippad med varme som alstras internt i testanordningen (30) av mottagarspolen (34) for tr5d1Os kraft; och den andra temperatursensorn (56) är anpassad att tillhandahalla matdata som indikerar en temperatur forknippad med omgivande luft runt testanordningen (30).

12. Testanordningen enligt nagot foregaende krav, dar de termosensoriska organen (31) vidare innefattar en tredje temperatursensor (55'), varvid den tredje temperatursensorn (55') är anpassad att mata en temperatur vid en tredje position, varvid den tredje positionen är inuti holjet (50) och skiljer sig fran den forsta positionen. 3

13. Testanordningen enligt krav 12, dar den tredje temperatursensorn (55') är placerad mellan mottagarspolen (34) for tr5dlos kraft och undersidan (53) p5 holjet (50), varvid den tredje temperatursensorn (55') är anpassad att tillhandahalla matdata som indikerar en temperatur forknippad med varme som alstras av sandarspolen (24) for tr6d1Os kraft hos sandaranordningen (20) for tr6dlos kraft.

14. Testanordningen enligt nagot foregaende krav, dar testanordningen är anpassad for anvandning med en sandaranordning (20) for tr6dlos kraft i form av en tradlos laddare (20).

15. Metod for att emulera en mobilanordnings termiska exponering nar den är foremal fOr tradlos kraftoverfOring fran en sandaranordning (20) for tradlos kraft vilken har en sandarspole (24) for tradlos kraft, varvid metoden inbegriper: att tillhandah51Ia (110) en testanordning (30) vilken har en mottagarspole (34) for tradlos kraft som Overensstammer med sandarspolen (24) for tradlos kraft och vilken har ett holje (50) med termiska absorptions- och avgivningsegenskaper som overensstammer med en mobilanordning som ska emuleras; att driva (120) sandaranordningen (20) for tradlos kraft under en drifttid (OT) for att alstra tradlos kraft till testanordningen (30); att mata (130) en forsta temperatur (T1) vid en forsta position inuti test- anordningens (30) hOlje (50) under drifttiden (OT); att mata (135) en andra temperatur (T2) vid en andra position som är utanfor testanordningens (30) holje (50) under drifttiden (OT); och att at ett bearbetningsorgan (42) tillhandahalla (150) matdata fran matningen av den forsta temperaturen och matningen av den andra temperaturen under drifttiden (OT).

16. Metoden enligt krav 15, vidare inbegripande: att registrera (160) namnda matdata med hjalp av bearbetningsorganet (42); och att utvardera (170), med hjalp av bearbetningsorganet (42), huruvida namnda matdata indikerar en I5ngsiktig avvikelse mellan den forsta temperaturen och den andra temperaturen overstigande ett troskelvarde under eller vid slutet av drifttiden (OT); och i sa fall(175), att alstra (180) en larmsignal (45). 4

17. Metoden enligt krav 15 eller 16, dar: den forsta positionen är mellan mottagarspolen (34) far tradlOs kraft och en ovansida (54) pa holjet (50) pa testanordningen (30), varvid matningen av den forsta temperaturen (Ti) indikerar en temperatur forknippad med varme som alstras internt i testanordningen (30) av mottagarspolen (34) for tradlOs kraft; och den andra positionen är pa ett avstand (61) fran holjet (50) pa testanordningen (30), varvid matningen av den andra temperaturen (12) indikerar en temperatur forknippad med omgivande luft runt testanordningen (30).

18. Metoden enligt krav 17, vidare inbegripande: att mata (140) en tredje temperatur (T3) vid en tredje position inuti holjet (50) pa testanordningen (30) under drifttiden (OT), varvid den tredje positionen skiljer sig fran den forsta positionen, dar namnda matdata som tillhandahalls (150) at bearbet- ningsorganet (42) inbegriper ocksa matningen av den tredje temperaturen.

19. Metoden enligt krav 18, dar den tredje positionen är mellan mottagarspolen (34) for tradlos kraft och undersidan (53) pa testanordningens (30) holje (50), varvid matningen av den tredje temperaturen (T3) indikerar en temperatur forknippad med varme som alstras av sandarspolen (24) for tradlos kraft has sandaranordningen (20) for tradlos kraft.