Charging device for wirelessly charging an electrical energy storage device and method for controlling a charging device

Abstract

A charging device (1) for wirelessly charging an electrical energy storage device (2) of a mobile terminal (3) is described. The charging device (1) has an air duct (6), a support (4) adjacent to the air duct (6) and having a support surface (5) for supporting the mobile terminal (3) on the support surface (5), a power transmission unit (9) for wirelessly transmitting power to the supported mobile terminal (3), at least one temperature sensor (15), and a charging controller (8) connected to the power transmission unit (9) and configured to control the power transmission from the power transmission unit (9) to the supported mobile terminal (3) using the temperature measured by the at least one temperature sensor (15). The at least one temperature sensor (15) is configured to measure the air temperature of the air flowing in the air duct (6). The charging controller (8) is configured to control at least one charging parameter for the energy transmitted by the energy transmission unit (9) and / or the air flow of the air flowing in the air duct (6) by means of the temperature (T Mobilgerät ) of the mobile terminal (3), wherein the temperature (T Mobilgerät ) of the mobile terminal (3) as a measure of the air inlet (L U ) in front of the area of the support surface (5) to the exit behind the area of the support surface (5) occurring increase (ΔT Luft ) the air temperature of the air flowing in the air duct (6) past the support surface (5) with the mobile terminal device (3) resting thereon (L W ) is determined.

Description

[0001] The invention relates to a charging device for wirelessly charging an electrical energy storage device of a mobile terminal, wherein the charging device comprises: - an air duct; - a support adjacent to the air duct with a support surface for supporting the mobile device on the support surface; - an energy transmission unit for wireless transmission of energy to the mobile terminal device; - at least one temperature sensor; and - a charging controller connected to the energy transfer unit and configured to control the energy transfer from the energy transfer unit to the mobile terminal device by means of the temperature measured by the at least one temperature sensor.

[0002] The invention further relates to a method for controlling such a charging device.

[0003] DE 10 2016 216 900 B1 describes a charging device for wirelessly charging a rechargeable electrical energy storage device of a mobile terminal, comprising a housing, a primary coil device, and a first control device operatively connected thereto. The first control device is arranged in the housing, which has at least one air inlet opening and at least one air outlet opening. A heat sink is arranged in the housing, to which an active air supply device, i.e., a fan, is assigned, with which ambient air is actively supplied to the heat sink through the at least one air inlet opening. A temperature sensor device for detecting the temperature of the heat sink is assigned to the heat sink.The charging device further comprises a second control device, which is in signal communication with the temperature sensor device and operatively coupled to the active air supply device, and which is configured to activate the active air supply device as soon as and as long as a predeterminable first limit temperature of the heat sink is reached or exceeded. Furthermore, the second control device is also in signal communication with the first control device and is configured to activate the active air supply device only if wireless charging of an electrical energy storage device of a mobile terminal is also performed when or after the first limit temperature of the heat sink is reached or exceeded.

[0004] DE 10 2019 211 519 A1 discloses a charging device for wirelessly charging an electrical energy storage device of a mobile terminal for a motor vehicle, wherein the charging device has charging electronics and a housing in which the charging electronics are arranged. The housing comprises a support area for supporting the mobile terminal, wherein the support area has at least two elevations extending in the direction of the length of the support area, each having a first predetermined height, which are arranged parallel to one another at a predetermined distance from one another and form an air duct when the mobile terminal is placed on the support area. The housing has at least one air inlet opening and at least one air outlet opening, wherein the air outlet opening is arranged in the support area and is designed to blow air into the air duct.Furthermore, at least one barrier is arranged in the air duct, which swirls the air blown into the air duct.

[0005] Charging mobile devices via inductive power transfer has become increasingly important. Similar to wired charging, where the mechanical and electrical standard via the micro-USB or USB-C interface has prevailed, inductive power transfer also has a transmission standard that allows the combination of charging devices and mobile devices from different manufacturers. In the world of wireless charging, the Qi standard of the WPC (Wireless Power Consortium) has become established, and is now supported by all major mobile device manufacturers. This standard offers defined power transfer of up to 5 watts in the low-power range and up to 15 watts in the medium-power range.

[0006] Some mobile device manufacturers have extended this standard specifically for their phones and are thus capable of transmitting power above 15 watts. During the charging process, in which electrical energy is converted into magnetic energy in the energy transfer device ("transmitter") and then magnetic energy is converted back into electrical energy in the mobile device being charged, losses occur in various circuit units of both the transmitter and the mobile device, which are dissipated in the form of heat energy. The higher the transmitted power, the greater the power loss and thus the heat generation.

[0007] The electrical energy in mobile devices is typically stored in lithium-ion batteries. According to the specifications for this type of battery, charging should only take place up to a temperature of approximately 45°C to ensure the longest possible battery life and to protect the battery from dangerous operating conditions that could lead to a fire, for example. This protective functionality is typically implemented in the mobile device itself, which is equipped with a temperature sensor near the battery.

[0008] Due to the significant consequences of faulty thermal protection in a mobile device, it is necessary to incorporate an additional protective function into the charging device. Even if charging is carried out at room temperature, the battery will heat up very quickly to the maximum permissible temperature due to the high losses in the transmitter and the mobile device. To stop this temperature increase, either the charging power must be reduced, the charging process must be turned off completely, or active cooling must be implemented.

[0009] Known cooling methods include those using the air flowing out of the vehicle's air conditioning system, or methods with a fan integrated into the transmitter, where ambient air is blown or sucked in between the transmitter contact surface and the mobile device. Furthermore, it is necessary to monitor whether the temperature exceeds the critical threshold despite the air cooling. For this purpose, one or more temperature sensors are typically located in or just below the transmitter contact surface. These sensors detect both an increase in temperature caused by the power components in the transmitter and an increase in temperature of the mobile device being charged due to losses in the receiver electronics, charging losses in the battery, and heat generation in the processor for the actual function of the mobile device, e.g., navigation.

[0010] The temperature sensor in the charging device traditionally detects the temperature increase in the mobile device by conducting heat energy from the mobile device's support side through the charger's support mat, across the charger's plastic housing surface, to the temperature sensor beneath the plastic housing surface. Since both the support mat and the plastic housing have thermal resistance, a temperature drop occurs across the direction of heat flow, causing the mobile device's temperature to be higher than the temperature at the sensor. If the material constants of the housing wall and support mat are known, the system can determine the temperature in the mobile device and reduce the charging power if the calculated temperature in the mobile device exceeds a certain limit.If the charger can be used with or without a support mat, or if different support mats can be used, a sufficiently accurate temperature of the mobile device cannot be calculated.

[0011] A further inaccuracy is that these temperature sensors are placed very close to the transmitting coils and are also heated by them. This can lead to the mobile device being calculated to be too high, and the transmitting power being reduced, even though the mobile device hasn't yet reached the critical temperature.

[0012] The object of the present invention is to provide an improved charging device and an improved method for controlling the charging process with such a charging device.

[0013] The object is achieved by the charging device having the features of claim 1 and by the method having the features of claim 9. Advantageous embodiments are described in the subclaims.

[0014] It is proposed that the at least one temperature sensor is configured to measure the air temperature of the air flowing in the air duct and that the charging control is configured to control at least one charging parameter for the energy transmitted by the energy transmission unit and / or the air flow of the air flowing in the air duct by means of the temperature of the mobile terminal, wherein the temperature of the mobile terminal is determined as a measure of the increase in the air temperature of the air flowing past the support surface with the mobile terminal resting thereon in the air duct from the inlet of the air in front of the region of the support surface to the outlet behind the region of the support surface.

[0015] The problem of an inaccurate determination of the temperature of the mobile device due to unknown material constants and associated thermal resistances between the mobile device and the temperature sensor is solved by drawing an air stream between the mobile device and the support surface and then measuring the temperature of the air.

[0016] This creates a wireless charging transmitter that features airflow cooling from the charging device and / or the mobile device placed on it, and in which the temperature of the mobile device and / or charging device is detected by measuring the temperature of the air flowing through it. The temperature information is used to control at least one charging and / or ventilation parameter to optimize charging time and / or protect the mobile device from overheating.

[0017] The mobile device rests on the support surface of the charging device. In this case, it is preferably provided that the mobile device does not rest directly over its entire surface, but rather rests at an appropriate distance from the charging surface using measures such as spacers on the charging surface. This creates an air gap between the charging surface or the air duct base and the mobile device. An air passage opening within the support surface, together with further guide elements, forms an air duct beneath the mobile device. Ambient air flows through the air duct on the underside of the mobile device, via which the wireless energy exchange also takes place, and through the air passage opening into the interior of the charger. There, the slightly warmed air can be used to further cool the electronics or can escape directly to the outside via an air outlet opening.The airflow is typically provided by an electrically driven fan located in the charging device. Air can be drawn in from the air duct or blown into it.

[0018] A temperature sensor is located in the air duct near the air outlet. After passing through the heated air, it acquires the temperature of the air and transmits a corresponding value to the charging controller. The charging controller can be implemented using software-controlled technology, either via a microprocessor or a microcontroller in the charging device.

[0019] The heat energy is transferred from the bottom of the mobile device to the air beneath it using the physical principle of heat conduction. It is then absorbed and stored by the air, which has a certain specific heat capacity. The greater the temperature difference between the bottom of the mobile device and the air, the more heat energy is transferred to the air and stored by it. Furthermore, the longer the air remains beneath the mobile device, the more heat energy is transferred, and the more the air heats up.

[0020] The following relationships apply: - the heating of the air is approximately proportional to the temperature difference between the underside of the mobile device and the ambient air sucked in; - the heating of the air is approximately inversely proportional to the air flow rate.

[0021] The airflow rate depends on the shape of the air duct and the fan's airflow rate. These values are known and do not change during the charging device's lifetime. The fan's airflow rate depends on its speed. This speed is determined by the control voltage of the charging electronics and is therefore also known.

[0022] A first temperature sensor can be arranged in the air duct upstream of the support surface in the direction of air flow, and a second temperature sensor can be arranged downstream of the support surface in the direction of air flow. The charging controller can be configured to determine the increase in air temperature from the difference between the temperatures measured by the first and second temperature sensors. The aforementioned first relationship is thus utilized to determine the increase in air temperature and thus to determine the heat energy transmitted by the mobile device.

[0023] The air supplied to the air duct before heat transfer by the mobile device has a temperature measured by the first temperature sensor. This first temperature corresponds to the a priori unknown temperature of the ambient air, which can be determined by measurement before charging begins or when the mobile device is not in the charging station with the second temperature sensor, by a first temperature sensor arranged in the air duct in front of the support surface in the direction of air flow, or by an air conditioning device that regulates the ambient temperature. Since the ambient air temperature in today's motor vehicles is kept constant at approximately 20°C to 25°C by the air conditioning systems, this value can simply be assumed. Significant deviations are only to be expected at the beginning of a journey, for example if the vehicle is completely cold in winter or has been exposed to direct sunlight in summer.

[0024] Therefore, the following relationship can be assumed: ΔTair~(proportional to)(Tmobile device−22°C) / Ufan.

[0025] The temperature difference ΔT Luft The air flowing past the mobile device, which is a measure of the amount of heat absorbed, can be calculated from the temperature difference of the air temperature T flowing out behind the mobile device in the direction of flow. Mobilgerät and the assumed ambient temperature of e.g. 22°C, which flows in front of the mobile device in the direction of flow, and the fan voltage U Lüfter The fan voltage U Lüfter is the control voltage of the fan, which is proportional to the air flow rate or air flow velocity passing the mobile device.

[0026] If all constant values dependent on the system are summarized in a constant K, the result is: ΔTair=K*(Tmobile device−22°C) / Ufan.

[0027] When converted, the temperature of the mobile device is: TMobile device=ΔTAir*UFan / K+22°C

[0028] From the rearranged formula it is also clear that the calculation of the temperature of the mobile device depends crucially on how accurately the temperature increase of the air can be determined, in particular how accurately the temperature of the sucked-in ambient air can be measured or calculated.

[0029] Typically, the temperature increase at the appropriate fan speed is only a few degrees °C. To achieve this, a first temperature sensor can be installed in the air duct at a position where the air has not yet been heated by the mobile device. The temperature measured at this sensor would then correspond to the ambient air. The formula would change as follows: TMobile device=(TAir−TEnvironment)*UFan / C*+TEnvironment.

[0030] With these two sensors, the temperature of the mobile device can now be calculated with sufficient accuracy. However, the disadvantage is that this requires two temperature sensors.

[0031] The charging device can have a fan connected to the air duct. This allows the air flow and, in particular, the air flow velocity—i.e., the volume of air flowing directly or indirectly past the mobile device per unit of time—to be varied by changing the fan speed. This is equivalent to selectively switching several fans connected in parallel on or off, or to the cyclical control of one or more fans. By varying the air flow rate, the second relationship mentioned above is used to determine the increase in air temperature and thus to determine the heat energy transferred by the mobile device.

[0032] The measurement of the temperature difference of the air flowing past the mobile device can be carried out with two different fan speeds or fan control voltages U Lüfter1 and U Lüfter2 For this purpose, the charging controller can be configured to control the fan to effect a first air flow velocity, which corresponds to the air flow rate passed past the mobile terminal, of the air flow in the air duct and to measure the first air temperature at the first air flow velocity, to control the fan to effect a second air flow velocity of the air flow in the air duct and to measure the second air temperature at the second air flow velocity, and to determine the increase in the air temperature from the difference between the measured first and second air temperatures.

[0033] The formula is basically the same as the one above. However, the ambient temperature is unknown and does not need to be measured, estimated, or supplied. With the two air flow velocities or fan drive voltages U Lüfter1 and U Lüfter2 The two formulas result: TMobile device=(TAir1−TEnvironment)*UFan1 / K+TEnvironment TMobile device=(TAir2−TEnvironment)*UFan2 / K+TEnvironment.

[0034] Subtracting the equations and then multiplying by K gives: 0=(TAir1−TAmbient)*ULan1−(TAir2−TAmbient)*ULan2 or converted (TAir1−TAmbience)*UFan1=(TAir2−TAmbience)*UFan2

[0035] Further rearranged, this results in: TAir1*UFan1−TAmbient*UFan1=TAir2*UFan2−TEnvironment*UFan2

[0036] Night Umgebung converted results in: TAir1*UFan1−TAir2*UFan2=TEnvironment*UFan1−TEnvironment*UFan2 TEnvironment=(TAir1*UFan1−TAir2*UFan2) / (UFan1−UFan2).

[0037] This allows the temperature of the ambient air to be calculated and incorporated into the original formula (T Mobilgerät = (T Luft1 - T Umgebung ) * U Lüfter1 / K + T Umgebung ) and thus the temperature increase and the temperature of the mobile device can be determined with sufficient accuracy.

[0038] This leads to the following formula: TMobile device=(TAir1−TEnvironment)*UFan1 / K+TEnvironment=TAir1*UFan1 / K−TEnvironment*UFan1 / K+TEnvironment=TEnvironment*(1−U Fan1 / K)+TAir1*UFan1 / K=(TAir1*UFan1−TAir2*UFan2) / (UFan1−UFan2)*(1−UFan1 / K)+TAir1*UFan1 / K.

[0039] With this method based on different fan speeds, two extreme cases are conceivable: a) a very high air speed, whereby the air can hardly heat up at all and the measured temperature is approximately the same as the ambient air, and b) a very low air velocity, where the air remains under the mobile device for a very long time and heats up almost to the temperature of the mobile device. In this case, however, there would be little cooling effect.

[0040] Therefore, it is advantageous to schedule cyclic measurement intervals during which the fan runs very slowly, with the temperature measured during these intervals being assumed to be the mobile device temperature. This eliminates the need for complex calculations of the mobile device temperature. This method with cyclic measurement intervals can be used in addition to or as an alternative to the methods described above.

[0041] For this purpose, the charging controller can be configured to cyclically control the fan during measurement intervals to reduce the airflow velocity in the air duct, to measure the air temperature present during the measurement interval at the reduced airflow velocity, and to determine the temperature of the mobile device proportional to the air temperature measured during the measurement interval. The reduction in the airflow velocity can also be achieved by switching off the fan. This essentially limits the airflow to a natural convective airflow.

[0042] The charging control may be configured to reduce or switch off the charging power and / or to increase the air flow velocity by controlling at least one charging parameter for the energy transmitted by the energy transmission unit.

[0043] If it is determined that the temperature of the mobile device exceeds a certain threshold, the charging electronics of the charging controller and / or the mobile device can take measures to prevent a further increase in temperature or to reduce it. These measures can include: - Reduction of charging power; - Switching off the charging power; - Increase the fan speed.

[0044] The method for controlling such a charging device for wirelessly charging an electrical energy storage device of a mobile terminal comprises the following steps: - measuring the temperature of the air flowing directly or indirectly past a mobile device in the air duct adjacent to the mobile device, and - Controlling at least one charging parameter for the energy transfer with the energy transfer unit and / or the air flow of the air flowing in the air duct by means of the increase in the air temperature of the air flowing past the support surface with the mobile terminal device resting thereon in the air duct from the inlet of the air in front of the support surface area to the outlet behind the support surface area.

[0045] A first temperature in the air duct in the air flow direction in front of the support surface and a second temperature in the air duct in the air flow direction behind the support surface can be measured and the increase in the air temperature can be determined from the difference between the first and second temperatures.

[0046] The method may comprise the steps of: - controlling the fan to effect a first air flow velocity of the air flow in the air duct and measuring the first air temperature at the first air flow velocity, - controlling the fan to effect a second air flow velocity of the air flow in the air duct and measuring the second air temperature at the second air flow velocity and - Determining the increase in air temperature from the difference between the measured first and second air temperatures.

[0047] At least one charging parameter for the energy transmitted by the energy transmission unit can be controlled to reduce or switch off the charging power and / or to control the air flow of the air flowing in the air duct by means of the increase in the air temperature of the air flowing past the support surface with the mobile terminal device resting thereon, occurring from the air inlet in front of the support surface area to the outlet behind the support surface area.

[0048] The invention is explained below using exemplary embodiments with the accompanying drawings. They show: Fig. 1 - Side sectional view of a charging device for wirelessly charging an electrical energy storage device of a mobile terminal; Fig. 2 - perspective top view of a support with air duct in the support surface; Fig. 3 - perspective top view of another embodiment of the support surface; Fig. 4 - enlarged detail view of the perspective rear view from Fig. 3.

[0049] Fig. 1 shows a side sectional view of a charging device 1 for wirelessly charging an electrical energy storage device 2 of a mobile terminal device 3.

[0050] There is a support 4 with a support surface 5 on which the mobile device 3 rests. It can be seen that between the support surface 5 and the mobile device 3 there is an air duct 6 in the form of an air gap between the underside of the mobile device 3 and an air duct base 7 of the support 4, through which ambient air L U Optionally, the ambient air L U can also be blown through the air duct 6 with the opposite flow direction.

[0051] The charging device 1 has a charging controller 8 and an energy transmission unit 9 connected thereto, comprising at least one transmitting coil 10 which is arranged on the support 4. The mobile terminal 3 has, adjacent to the at least one transmitting coil 10, a corresponding receiving coil 11 for receiving the electromagnetic field generated by the transmitting coil 10. The energy transmission unit 9 is designed for wirelessly charging the electrical energy storage device 2 (in particular a rechargeable battery) of the mobile terminal 3 using the energy absorbed by the charging device 1 via the receiving coil 11. For this purpose, a wireless communication interface can also be provided in order to exchange charging parameters between the charging controller 8 of the charging device and a charging controller (not shown) of the mobile terminal 3. This can be done in the return channel by signaling via the receiving coil 11 and the transmitting coil 10, for example.by briefly changing the load applied to the receiving coil 11.

[0052] The air L flows along the underside of the mobile terminal 3 and is warmed, ie heated, by the heat of the mobile terminal 3. The now heated air L W is sucked into the interior of the charging device 1 through an air passage opening 12 in the support surface 5, guided through a fan 13 and released into the environment at another location. The air passage opening 12, through which the heated air L W from the air duct 6 into the charging device 1 can be located at different locations. Fig. 1 and Fig. 2, the air passage opening 12 is shown near the front side of the charger 1. In the Fig. 3, however, the air passage opening 12 is located on one side.

[0053] Fig. Figure 2 shows a perspective top view of the support 4 of the charging device 1 with air ducts 6 incorporated into the support surface 5. These are delimited by an air duct base 7 and support webs 14. It can be clearly seen that the structure of the support surface 5, together with the underside of a mobile device 3 placed thereon, forms three air flow channels 6, which end at the air passage opening 12. Not shown is the fan 13, which is located below the air passage opening 12 and supplies air L U sucked into the charging device 1 or blown out into the air ducts 6. Depending on the air flow direction, the air passage opening 12 can be an air inlet opening or an air outlet opening. The ambient air L U, which is sucked from under the mobile device 3, is heated both by the higher temperature of the mobile device 3 and the possibly higher temperature of the support surface 5, whereby the temperature increase is caused by the losses of the transmitting coils 10.

[0054] If there is a metallic foreign body in the air duct 6, e.g. a paper clip or a small coin, which is heated by the eddy currents, this also ensures that the sucked-in air L is heated. U In this case, the calculated temperature T Mobilgerät of the mobile terminal 3 does not correspond to the temperature of the mobile device 3, but the result of the power reduction or power shutdown is also desired in order to avoid a hazard caused by excessive heating of the foreign body.

[0055] Fig. 3 shows a perspective view of another embodiment of the support 4 of a charging device 1. The air passage opening 12 can be seen, which in this embodiment is arranged on one side of the air duct 6. A support mat (not shown) is placed on the surface, which is designed with openings and webs so that the air under the mobile device 3 placed thereon is guided into the air passage opening 12 of the support 4. A temperature sensor 15 is arranged on one side of the air passage opening 12, which measures the temperature of the heated air L behind the mobile device 3 in the flow direction. W measures.

[0056] Fig. Figure 4 shows this area again in an enlarged format. The heated air L W flows past the temperature sensor 15 and also heats it to the temperature level of the heated air L W. If no mobile terminal 3 is attached, the temperature sensor 15 detects the ambient temperature of the ambient air L U at the location of the support surface 5. This does not necessarily have to be the interior temperature of a vehicle in which the charging device 1 may be installed, because the support surface 5 could still be warm from the previous charging process. To reliably measure the air temperature in the interior of the vehicle, the fan 13 can be switched on, even if no mobile device 3 is resting on it, in order to directly suck in interior air. When the mobile device 3 is resting on it, the sucked-in ambient air L U by the mobile device 3, under which it is sucked or blown. Thus, this temperature difference between the temperature of the ambient air L U and the heated air L W a measure of the temperature of the mobile device. This temperature difference reflects the heat absorption of the mobile device 3.

[0057] Depending on the preconditions, the following options are advantageous for the process of cooling and protecting the mobile terminal 3: 1. There is no mobile device 3 on the support surface. Then the ambient temperature can be continuously recorded. 2. A mobile device is placed on the support surface and charging begins. Fan 13 is then switched on at a predetermined speed. The speed of fan 13 is regulated depending on the measured air temperature and the resulting calculated temperature of the mobile device 3. 3. Mobile device 3 is charging and is heating up. If the calculated temperature of mobile device 3 is above a first critical value despite the fan speed being at maximum, the charging power is reduced. If the calculated temperature of mobile device 3 is above a second critical value despite the fan speed being at maximum, charging is shut off completely. List of reference symbols 1 charging device 2 electrical energy storage 3 mobile device 4th edition 5 Support surface 6 Air duct 7 Air duct floor 8 Charging control 9 Energy transfer unit 10 transmitting coil 11 Receiving coil 12 Air passage opening 13 fans 14 support bars 15 Temperature sensor L U Ambient air L W heated air QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2016 216 900 B1

[0003] DE 10 2019 211 519 A1

[0004]

Claims

[1] Charging device (1) for wirelessly charging an electrical energy storage device (2) of a mobile terminal (3), the charging device (1) comprising: - an air duct (6); - a support (4) adjacent to the air duct (6) with a support surface (5) for supporting the mobile terminal (3) on the support surface (5); - an energy transmission unit (9) for wirelessly transmitting energy to the mobile terminal (3) located thereon; - at least one temperature sensor (15); and - a charging controller (8) connected to the energy transmission unit (9) and configured to control the energy transmission from the energy transmission unit (9) to the mounted mobile terminal (3) by means of the temperature measured by the at least one temperature sensor (15); characterized byin that the at least one temperature sensor (15) is designed to measure the air temperature of the air flowing in the air duct (6) and the charging control (8) is designed to control at least one charging parameter for the energy transmitted by the energy transmission unit (9) and / or the air flow of the air flowing in the air duct (6) by means of the temperature measured by the at least one temperature sensor (15). [2] Loading device (1) according to claim 1, characterized by that the charging control (8) is configured to control at least one charging parameter for the energy transmitted by the energy transmission unit (9) and / or the air flow of the air flowing in the air duct (6) by means of the temperature (T Mobilgerät ) of the mobile terminal (3), wherein the temperature (T Mobilgerät ) of the mobile terminal (3) as a measure of the air inlet (L U) in front of the area of the support surface (5) to the exit behind the area of the support surface (5) occurring increase (ΔT Luft ) the air temperature of the air flowing in the air duct (6) past the support surface (5) with the mobile terminal device (3) resting thereon (L W ) is determined. [3] Loading device (1) according to claim 2, characterized by that a first temperature sensor (15) is arranged in the air duct (6) in the air flow direction behind the support surface (5) and the charging control (8) for determining the increase (ΔT Luft ) of the air temperature from the difference between the temperature (T Luft ) and a measured ambient temperature (T Umgebung ) is set up. [4] Loading device (1) according to claim 3, characterized bythat a second temperature sensor is arranged in the air duct (6) in the air flow direction in front of the support surface (5) and the charging control (8) for determining the increase (ΔT Luft ) of the air temperature from the difference between the temperatures measured with the first and second temperature sensors (T Luft1 , T Umgebung ) is set up [5] Loading device (1) according to one of claims 1 to 4, characterized by that the charging device (1) has a fan (13) communicating with the air duct (6). [6] Loading device (1) according to claim 5, characterized by that the charging control (8) for controlling the fan (13) to effect a first air flow velocity of the air flow in the air duct (6) and for measuring the first air temperature (T Luft1) at the first air flow speed, for controlling the fan (13) to effect a second air flow speed of the air flow in the air duct (6) and for measuring the second air temperature (T Luft2 ) at the second air flow velocity and to determine the temperature (T Mobilgerät ) of the mobile device (3) or the increase (ΔT Luft ) of the air temperature from the difference (T Luft1 * U Lüfter1 - T Luft2 * U Lüfter2 ) / (U Lüfter1 - U Lüfter2 ) * (1- U Lüfter1 / K) + T Luft1 * U Lüfter1 / K) of the measured first and second air temperature (T Luft1 , T Luft1 ) is set up. [7] Loading device (1) according to claim 5 or 6, characterized bythat the charging control (8) is designed to cyclically control the fan (13) in measuring intervals to effect a reduced air flow velocity of the air flow in the air duct (6) and to measure the air temperature (T Luft ) at the reduced air flow velocity and to determine the temperature (T Mobilgerät ) of the mobile terminal (3) proportional to the air temperature (T Luft ) is set up. [8] Charging device (1) according to one of the preceding claims, characterized by that the charging control (8) is configured to reduce or switch off the charging power and / or to increase the air flow velocity by controlling at least one charging parameter for the energy transmitted by the energy transmission unit (9). [9] Method for controlling a charging device (1) according to one of the preceding claims for wirelessly charging an electrical energy storage device (2) of a mobile terminal (3), characterized by the steps: - measuring the air temperature of the air flowing directly or indirectly past the mobile terminal (3) in the air duct (6) adjacent to a mobile terminal (3), and - Controlling at least one charging parameter for the energy transfer with the energy transfer unit (9) and / or the air flow of the air flowing in the air duct (6) by means of the measured air temperature. [10] Method for controlling a charging device (1) according to one of the preceding claims, characterized by Controlling the at least one charging parameter for the energy transfer with the energy transfer unit (9) and / or the air flow of the air flowing in the air duct (6) by means of the temperature (T Mobilgerät) of the mobile terminal (3), which is a measure of the increase (ΔT Luft ) the air temperature of the air flowing past the support surface (5) in the air duct (6) with the mobile terminal device (3) resting thereon. [11] Method according to claim 10, characterized by Measuring a first temperature in the air duct (6) in the air flow direction behind the support surface (5) and determining the increase (ΔT Luft ) of the air temperature from the difference of the measured first temperature (T Luft ) and a measured ambient temperature (T Umgebung ). [12] Method according to claim 10, characterized by Measuring a first temperature (T Umgebung ) in the air duct (6) in the air flow direction in front of the support surface (5) as a temperature corresponding to the ambient temperature (TUmgebung ) proportional size and determining the increase in air temperature (ΔT Luft ) from the difference between the first and second temperatures (T Luft - T Umgebung ). [13] Method according to one of claims 10 to 12, characterized by - controlling the fan (13) to effect a first air flow velocity of the air flow in the air duct (6) and measuring the first air temperature (T Luft1 ) at the first air flow velocity, - controlling the fan (13) to effect a second air flow velocity of the air flow in the air duct (6) and measuring the second air temperature (T Luft2 ) at the second air flow velocity, and - Determine the temperature (T Mobilgerät ) of the mobile device (3) or the increase in air temperature (ΔT Luft ) from the difference between the measured first and second air temperatures (T Luft1 * U Lüfter1 - T Luft2 * U Lüfter2) / (U Lüfter1 - U Lüfter2 ) * (1- U Lüfter1 / K) + T Luft1 * U Lüfter1 / K). [14] Method according to one of claims 9 to 13, characterized by cyclically controlling the fan (13) in measuring intervals to effect a reduced air flow velocity of the air flow in the air duct (6), measuring the air temperature (T Luft ) at the reduced air flow velocity and determining the temperature (T Mobilgerät ) of the mobile terminal (3) proportional to the air temperature (T Luft ). [15] Method according to one of claims 9 to 14, characterized byControlling at least one charging parameter for the energy transmitted by the energy transmission unit (9) to reduce or switch off the charging power and / or controlling the air flow of the air flowing in the air duct (6) by means of the increase in the air temperature (ΔT Luft ) of the air flowing in the air duct (6) past the support surface (5) with the mobile terminal device (3) resting thereon.

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