JP6743948B2 - Terminal device - Google Patents

Description

The present disclosure relates to a terminal device.

It has been conventionally performed that a device such as a charging device supplies power to a terminal device in a non-contact state in which terminals and the like are not directly connected.
An electromagnetic induction method is known as a conventional non-contact power transmission method. In this system, a power transmission coil is arranged in a device that transmits electric power, and a power reception coil is arranged in a reception side terminal device. In this electromagnetic induction method, the place where the power transmission coil of the device on the transmission side is arranged and the place where the power reception coil of the device on the reception side is arranged are close to each other, and the two coils are magnetically coupled and contactless. The process of sending electric power is performed.

A magnetic field resonance method has been developed as a method for efficiently supplying electric power to a terminal device that is separated by a certain distance in a non-contact manner. In this system, an LC circuit including a coil and a capacitor is provided in each of the power transmission side device and the power reception side device, and electric power and magnetic field are resonated between both circuits to wirelessly transmit electric power.

In both cases of the electromagnetic induction method and the magnetic field resonance method, the power transmission side device includes the power transmission coil, and the power reception side device includes the power reception coil. In the following description of the present specification, the electromagnetic induction method also includes other similar non-contact power transmission methods such as a magnetic field resonance method.

FIG. 11 is a diagram showing a configuration example in which power is fed from a conventional power feeding device to a terminal device in a contactless manner by an electromagnetic induction method.
The power supply device 10, which is a primary device, converts an AC power supply 11 such as AC100V into a DC low-voltage power supply by an AC-DC converter 12. The DC low-voltage power supply obtained by the AC-DC converter 12 is supplied to the power transmission driver 13. A power transmission circuit in which a capacitor 14 and a primary coil 15 are connected is connected to the power transmission driver 13, and the power transmission driver 13 supplies the primary coil 15 with transmission power having a predetermined frequency.

In the terminal device 20 which is the secondary side device, the secondary side coil 21 and the capacitor 22 are connected to the rectification unit 23, and the secondary side coil 21 receives the power from the primary side coil 15.
The series circuit of the secondary coil 21 and the capacitor 22 is connected to the rectifying unit 23, and the rectifying unit 23 rectifies the received power source to obtain the DC power source of the predetermined voltage Va. As the predetermined voltage Va, for example, a DC power slightly exceeding 5V is obtained.

The DC power source obtained by the rectifying unit 23 is supplied to the regulator 24 and converted into a constant voltage (for example, 5V). The constant-voltage DC power source obtained by the regulator 24 is supplied to the charging control unit 25, and the secondary battery 26 is charged under the control of the charging control unit 25.

When such a contactless power feeding system is configured, the regulator 24 of the secondary device normally has a relatively small difference between the input voltage and the output voltage, which is called LDO (Low Drop Out). If applicable series regulator is used. By using LDO as the regulator 24, it is possible to construct a system having a high efficiency to some extent for low power reception of about 5 W.

By the way, in the case of non-contact power transmission, there is a demand for increasing the transmission power. That is, in the non-contact power feeding system currently put into practical use, the power received by the terminal device is a relatively small power of about 1 W to 5 W. On the other hand, there is a demand for the terminal device to obtain larger received power such as 10 W or 15 W by non-contact transmission by the electromagnetic induction method.

Here, in the case of receiving a large amount of electric power with the configuration shown in FIG. 11, the regulator 24 using the LDO has a problem that a large current flows and the loss of the coil is large.

A switching regulator called a so-called DC-DC converter is known as a regulator that handles relatively large electric power and high voltage.
Patent Document 1 describes that in a power supply device, a regulator using LDO and a switching regulator are used together. This patent document 1 describes that a switching regulator is used at the time of heavy load, and a LDO regulator is used at the time of light load.

JP, 2010-183812, A

Conventionally, as described in Patent Document 1 and the like, in a power supply device such as an AC adapter, when a regulator using an LDO and a switching regulator are used together, the voltage of the input power supply is detected to switch between the two regulators. I have to.
Here, the same configuration cannot be applied to the regulator of the secondary device of the contactless power feeding system as shown in FIG. 11. That is, when the contactless power feeding system shown in FIG. 11 is configured, the input voltage Va of the regulator 24 in the terminal device 20 is substantially constant, and when the received power increases, the current only increases. Therefore, the configuration in which the regulator is switched by detecting the input voltage cannot be applied.

Here, an example in which the power receiving coil generates heat due to a change in received power will be described with reference to the table in FIG.
In the example of FIG. 12, three examples of the received power of 5 W, 10 W, and 15 W are shown. In any of the examples, when the rectifying unit 23 rectifies to 5 V, the current value becomes 1 A when the received power is 5 W, 2 A when the received power is 5 W, and 3 A when the received power is 5 W. Since the resistance value of the secondary coil 21 is determined by the cross-sectional area of the secondary coil 21, it is constant at any power. In the example of FIG. 12, the resistance value of the secondary coil 21 is 0.4Ω. The power loss of the secondary coil 21 is determined by the product of the square of the current and the resistance value from the equation of Q=I2R, and the power loss increases as the current increases. Here, when the conversion formula between the secondary power loss and the temperature is 20° C./0.6 W, the heat generation temperature of the secondary coil 21 at each received power changes as shown in FIG. That is, when the received power is 5 W, the temperature is about 13° C., when the power is 10 W, the temperature is about 53° C., and when the received power is 15 W, the temperature is about 120° C.

In FIG. 12, the conversion formula between the secondary side power loss and the temperature is set to 20° C./0.6 W because the temperature characteristics of the two types of terminal devices equipped with the coil for non-contact power feeding are measured. based on. That is, as shown in FIG. 13, when a temperature characteristic T1 of a certain type of terminal device and a temperature characteristic T2 of another type of terminal device are measured, the temperature rises substantially linearly with the change in loss power. was gotten. From the characteristics obtained by linearly approximating these characteristics T1 and T2, a conversion formula of 20° C./0.6 W was obtained.

By the way, as a problem different from heat generation, when a secondary side device uses a switching regulator, there is a problem in efficiency when receiving power supply with a small amount of power. That is, FIG. 14 is a diagram showing the relationship between the received power and the received frequency, the characteristic W1 is for the regulator using LDO, and the characteristic W2 is for the switching regulator. As can be seen by comparing these characteristics W1 and W2, for example, in the case of the characteristic W1 using LDO, the received power becomes high in the vicinity of the specific frequency band. On the other hand, in the case of the characteristic W2 using the switching regulator, the received power becomes low in the frequency band where the received power is high in the characteristic W1.

As described above, there is a problem in that the appropriate carrier frequency changes depending on the regulator system included in the secondary device, and the regulator system cannot be easily selected.

An object of the present disclosure is to solve problems such as heat generation and inefficiency when the amount of transmitted power is increased when a contactless power feeding system is assembled.

The terminal device of the present disclosure is
A power receiving unit that receives the power sent from the power feeding device in a contactless manner,
A rectifying unit that obtains a voltage by rectifying the received power obtained by the power receiving unit,
A regulator that converts the voltage output from the rectification unit into a predetermined voltage using the first processing unit or the second processing unit;
A control unit that calculates a power reception efficiency of the power supplied from the power supply device;
The control unit adjusts the voltage output from the rectification unit by the first processing unit in the regulator, the second processing unit, or stops the regulator based on the power reception efficiency. Control what to do.

According to the present disclosure, the regulator included in the terminal device that receives the power transmitted from the power supply device is set to perform an appropriate voltage transformation operation.

According to the present disclosure, an appropriate conversion method and input power can be set, and power can be properly received.

FIG. 1 is a block diagram showing a system configuration example according to an embodiment of the present disclosure. FIG. 7 is a characteristic diagram illustrating a variation example of received power according to an embodiment of the present disclosure. FIG. 3 is a block diagram showing a configuration example (example 1) of a regulator according to an embodiment of the present disclosure. It is a figure which shows the operation state of the regulator of the example of FIG. FIG. 3 is a block diagram showing a configuration example (example 2) of a regulator according to an embodiment of the present disclosure. FIG. 3 is a block diagram showing a configuration example (example 3) of a regulator according to an embodiment of the present disclosure. 7 is a flowchart showing an operation example (an example of communication from the primary side) according to the embodiment of the present disclosure. 9 is a flowchart showing an operation example (an example of communication from a secondary side) according to an embodiment of the present disclosure. 9 is a flowchart showing an operation (variation 1: example of controlling by temperature) according to an embodiment of the present disclosure. 9 is a flowchart showing an operation according to an embodiment of the present disclosure (Modification 2: an example of controlling by efficiency). It is a block diagram which shows the conventional system configuration example. It is a characteristic view by the example of a change of the received electric power by the example of FIG. It is a characteristic view which shows the heat generation example of the conventional terminal device. It is a characteristic view which shows the example of the received electric power for every system of a regulator.

Examples of the non-contact power feeding system, the terminal device, the non-contact power feeding device, and the non-contact power feeding method according to the embodiments of the present disclosure will be described in the following order with reference to the drawings.
1. Configuration example of power supply device and terminal device (Figs. 1-2)
2. Example of regulator (Example 1: Figures 3-4)
3. Example of regulator (Example 2: Figure 5)
4. Example of regulator (Example 3: Figure 6)
5. Power supply processing example (Example 1: Figure 7)
6. Power supply processing example (Example 2: Figure 8)
7. Modification of power supply processing (Modification 1: FIG. 9)
8. Modification of power supply processing (Modification 2: FIG. 10)
9. Other variants

[1. Configuration example of power supply device and terminal device]
FIG. 1 is a diagram illustrating a configuration example of a contactless power feeding system according to an example of an embodiment of the present disclosure.
The contactless power supply system of the present disclosure includes a power supply device 100 that is a primary device and a terminal device (power receiving device) 200 that is a secondary device, and supplies power in a contactless manner by an electromagnetic induction method. The power supply device 100 is a device that receives supply of commercial AC power or the like and supplies power to the terminal device 200 in a contactless manner. The terminal device 200 includes a load circuit that operates with the power supplied from the power supply device 100. Alternatively, the terminal device 200 may include a secondary battery that is charged by the power supply supplied from the power supply device 100. The terminal device 200 can be applied to various terminal devices (electronic devices) such as a mobile phone terminal device and a portable audio reproducing device.

The power supply device 100, which is a primary device, converts an AC power supply 101 such as AC100V into a DC low-voltage power supply with an AC-DC converter 102. The DC low-voltage power supply obtained by the AC-DC converter 102 is supplied to the power transmission driver 103. The use of the AC power supply 101 is one example, and a DC power supply may be used as the input power supply, for example.
The power transmission driver 103 is connected to a power transmission circuit in which a capacitor 105 and a primary coil 106 are connected, and the power transmission driver 103 supplies transmission power of a predetermined frequency to the primary coil 106.

The power feeding device 100 includes a control unit (primary side control unit) 104 that controls a power feeding process, and the control unit 104 controls the transmission power supplied from the power transmission driver 103 to the primary side coil 106. The power supply apparatus 100 of the example of the present embodiment is configured such that the transmission power can be variably set in a plurality of stages, and the control unit 104 sets one of the transmission power values in the plurality of stages. A specific example of setting the transmission power will be described later.

The power supply apparatus 100 also includes a communication unit 107, and the communication unit 107 bidirectionally communicates with the terminal device 200. The communication by the communication unit 107 is performed, for example, by superimposing a transmission signal on the transmission power supplied from the power transmission driver 103 to the primary coil 106. Specifically, the frequency of the transmission power supplied to the primary coil 106 is used as a carrier wave to modulate and transmit information by ASK (amplitude shift keying) or the like. Information is also transmitted from the terminal device 200 side to the communication unit 107 by the same method. Alternatively, the transmission of information from the terminal device 200 side to the communication unit 107 may be transmission using a subcarrier different from the frequency of the transmitted power. As a method of bidirectionally transmitting information together with electric power between adjacent coils in a non-contact manner, various methods have already been put into practical use for communication between a non-contact IC card and a reader, etc. In the above example, either method may be applied.

Next, the terminal device 200, which is a secondary device, will be described.
In the terminal device 200, the secondary coil 201 and the capacitor 202 are connected to the rectifying unit 203, and the secondary coil 201 receives the power from the primary coil 106. In the case of the electromagnetic induction method, usually, the primary coil 106 and the secondary coil 201 are arranged in close proximity to each other. The rectification unit 203 rectifies the power of a predetermined frequency received by the secondary coil 201 to obtain a DC power supply.

Then, the DC power source obtained by the rectifying unit 203 is supplied to the regulator 210. The regulator 210 is a voltage converter that converts the voltage of the input power supply into a predetermined voltage, and the DC power of the predetermined voltage obtained by the regulator 210 is supplied to the load circuit 204. A secondary battery may be charged instead of the load circuit 204.

The regulator 210 of the example of the present disclosure is configured to perform a conversion operation of received power by a plurality of methods. In the example of FIG. 1, the regulator 210 includes two types of conversion circuits, a DC-DC converter 211 and an LDO 212.
The DC-DC converter 211 is called a switching regulator, and is a circuit that switches an input power supply with a switching element at a relatively high speed, rectifies and smoothes the switched power supply, and converts the input power supply into a DC power supply having a desired voltage. The DC-DC converter 211 has a wide variable range of the input voltage.

An LDO (Low Drop Out) 212 is a series regulator that controls a voltage drop amount in a transistor element and uses it as a DC power supply of a desired voltage. The LDO 212 has a narrow variable range of the input voltage, and when the input voltage is slightly higher than the output voltage, efficient voltage conversion is performed.

The regulator 210 uses one of the DC-DC converter 211 and the LDO 212 to convert the voltage of the input power source into a stable constant voltage. The circuit used by the regulator 210 for the conversion operation is determined by an instruction from the control unit (secondary side control unit) 205 that controls power reception. In the example of the present disclosure, the DC-DC converter 211 is used when the input voltage is a relatively high voltage, and the LDO 212 is used when the input voltage is a relatively low voltage. Details of the selection operation of the DC-DC converter 211 and the LDO 212 under the control of the control unit 205 will be described later.

Further, the terminal device 200 includes a communication unit 206, and bidirectionally communicates with the communication unit 107 on the power feeding device 100 side. In order for the communication unit 206 to perform communication, a series circuit of the secondary coil 201 and the capacitor 202 is connected to the communication unit 206 and detects a signal superimposed on the power source supplied from the power supply apparatus 100. Then, the signal transmitted from the communication unit 107 is received. Further, the signal transmitted from the communication unit 206 is supplied to the series circuit of the secondary coil 201 and the capacitor 202.
Further, the terminal device 200 includes a temperature sensor 207 and measures the temperature in the vicinity of the secondary coil 201. The temperature data measured by the temperature sensor 207 is supplied to the control unit 205.

The non-contact power feeding system of the present disclosure has at least three stages of power feeding from the power feeding device 100 to the terminal device 200, that is, 5 W, 10 W, and 15 W. You can set the power supply to. Then, when the terminal device 200 receives the supplied power, the input voltage Vx of the regulator 210 corresponding to the supplied power is set, and the received power of the input voltage Vx is converted by the regulator 210 into a constant voltage. Output. The setting of the input voltage Vx in the regulator 210 is performed under the control of the control unit 205. At this time, the control unit 205 controls to perform the conversion operation by using the DC-DC converter 211 or the LDO 212, whichever is appropriate, as described above.

FIG. 2 is a diagram showing an example of power supply power, power reception voltage at the terminal device 200 (that is, input voltage Vx at the regulator 210), power loss, and heat generation. The conditions for generating heat are the same as those shown in FIG. 12 shown as a conventional example.
In FIG. 2, three examples of 5 W power feeding, 10 W power feeding, and 15 W power feeding are shown.
When the power feeding apparatus 100 performs power feeding in each of 5 W, 10 W, and 15 W, in this example, the input voltage Vx (secondary side voltage) in the regulator 210 is set to 5 V, 10 V, and 15 V, respectively, and the terminal device 200 In any case, the secondary current obtained in step 1 is set to about 1A.

The resistance value of the secondary coil 201 is the same in all examples, and the secondary current is 1 A at any supplied power, so the secondary power loss is 0.4 W at any power. become. Therefore, the heat generation temperature of the secondary coil 201 is about 13° C. for any power. The heat generation temperature shown in FIG. 2 is calculated under the conditions (20° C./0.6 W) set in the example of FIG.

[2. Example of regulator (Example 1)]
Next, an example of a specific configuration of the regulator 210 will be described. Here, three examples of Example 1, Example 2, and Example 3 will be described.

FIG. 3 is a diagram illustrating the configuration of the regulator 210 of the first example.
In the configuration shown in FIG. 3, the DC-DC converter 211 and the LDO 212 are connected in series. In the example of FIG. 3, the LDO 212 is connected after the DC-DC converter 211, but the connection order may be reversed. Then, only one of the DC-DC converter 211 and the LDO 212 operates. The stopped side of the DC-DC converter 211 and the LDO 212 outputs the input signal as it is.

FIG. 4 is a diagram showing an operating state of the regulator 210 of the example of FIG. When using the DC-DC converter 211, as shown in FIG. 4A, the control unit 205 operates the DC-DC converter 211 to pass the LDO 212. By doing so, the power source converted by the DC-DC converter 211 is obtained at the output section of the regulator 210.

Further, when using the LDO 212, as shown in FIG. 4B, the control unit 205 activates the LDO 212 to pass the DC-DC converter 211. By doing so, the power source converted by the LDO 212 is obtained at the output section of the regulator 210.

[3. Example of regulator (Example 2)]
FIG. 5 is a diagram illustrating the configuration of the regulator 210 of the second example.
In the configuration shown in FIG. 5, the DC-DC converter 211 and the LDO 212 are connected in parallel. Then, the side on which the control unit 205 operates is controlled so that only one of the DC-DC converter 211 and the LDO 212 operates.

[4. Example of regulator (Example 3)]
FIG. 6 is a diagram illustrating the configuration of the regulator 210 of the third example.
In the configuration shown in FIG. 6, the DC-DC converter 211 and the LDO 212 share a circuit.
As shown in FIG. 6, two transistors Q1 and Q2 are connected between the input terminal 210a of the regulator 210 and the ground potential portion. The control unit 205 controls ON/OFF of the two transistors Q1 and Q2. The connection point of both transistors Q1 and Q2 is connected to the output terminal 210b of the regulator 210 via the coil L1. One end of a smoothing capacitor C1 is connected to a connection point between the coil L1 and the output terminal 210b.

A series circuit of resistors R1 and R2 for voltage detection is connected between the connection point between the transistors Q1 and Q2 and the coil L1 and the ground potential portion. Further, a series circuit of resistors R3 and R4 for voltage detection is connected between the connection point between the coil L1 and the output terminal 210b and the ground potential portion. The control unit 205 detects the voltage at the connection point between the resistors R1 and R2 and the voltage at the connection point between the resistors R3 and R4.

When the regulator 210 is used as the DC-DC converter 211 in the configuration shown in FIG. 6, the control unit 205 turns on and off the two transistors Q1 and Q2 at high speed to perform the switching operation. At this time, the control unit 205 monitors the voltage charged in the smoothing capacitor C1 from the voltage at the connection point of the resistors R3 and R4, and the two transistors Q1 are arranged so that the detected voltage becomes appropriate. , Q2 control the switching state.

Further, in the configuration shown in FIG. 6, when the regulator 210 is used as the LDO 212, the transistor Q1 is controlled to serve as a voltage control element. The control unit 205 sets the transistor Q2 in an open state. At this time, the control unit 205 detects the voltage at the connection point of the resistors R1 and R2 and controls the voltage drop amount in the transistor Q1 so that the voltage becomes appropriate.

[5. Power supply processing example (Example 1)]
Next, an example of power supply processing performed between the power supply device 100 and the terminal device 200 will be described. Here, two examples will be described, an example 1 (FIG. 7) in which processing is performed by communication from the power supply apparatus 100 and an example 2 (FIG. 8) in which processing is performed by communication from the terminal device 200. In either case, the primary coil 106 of the power feeding apparatus 100 and the secondary coil 201 of the terminal apparatus 200 are in a state of being close to a state in which power transmission is possible.

FIG. 7 is a flowchart illustrating an example of power supply processing of the first example.
The process will be described with reference to FIG. 7. First, the control unit 104 of the power supply apparatus 100, which is a primary device, starts supplying the transmission power from the power transmission driver 103 to the primary coil 106 (step S11). At this time, a relatively low power for starting is set. That is, the control unit 104 sets a power lower than the power such as 5 W and 15 W described above. The low power for startup may be power that enables communication between the primary side communication unit 107 and the secondary side communication unit 206. Alternatively, the control unit 104 may set 5W, which is the smallest electric power among the electric powers that can be set in a plurality of stages described above, as the transmission power for startup.

By starting the power transmission in this way, the communication unit 206 and the control unit 205 of the terminal device 200, which is the secondary device, are activated (step S12). When this activation is performed, a signal indicating activation may be transmitted from the communication unit 206 of the terminal device 200 to the communication unit 107 of the power supply apparatus 100.

Then, when the secondary device is activated, the control unit 104 of the power supply apparatus 100 transmits a signal confirming the load power required by the load circuit 204 of the terminal device 200 from the communication unit 107 (step S13). When the communication unit 206 of the terminal device 200 receives the signal confirming the load power, the control unit 205 returns information indicating the load power from the communication unit 206, and the control unit 104 of the power supply apparatus 100 transmits the information. Check the load power.

Then, the control unit 104 determines the transmission power corresponding to the confirmed load power (step S14). For example, the control unit 104 selects transmission power that is equal to or greater than the load power.
At this time, the control unit 104 may transmit the determined transmission power information from the communication unit 107 to the terminal device 200.

The control unit 205 of the terminal device 200 determines from the information received by the communication unit 206 whether the transmission power is equal to or higher than the threshold THx or lower than the threshold THx.
Here, when the transmission power is equal to or higher than the threshold value THx, the control unit 205 instructs to use the DC-DC converter 211 as the regulator 210 (step S15).
When the transmission power is less than the threshold value THx, the control unit 205 instructs to use the LDO 212 as the regulator 210 (step S16). The input voltage of the regulator 210 is set appropriately based on, for example, the transmission power. As an example, when it is desired to keep the current constant, the control unit 205 sets any one of the input voltages 5V, 10V, and 15V corresponding to the transmission power 5W, 10W, and 15W, as shown in FIG.

Then, the control unit 104 of the power supply apparatus 100 starts power supply with the transmission power determined in step S14 (step S17).
As described above, according to the process of the flowchart of FIG. 7, the regulator 210 in the terminal device 200 uses the DC-DC converter 211 or the LDO 212, whichever is appropriate, based on the transmission power instructed from the power supply device 100. It comes to perform voltage conversion.

[6. Power supply processing example (Example 2)]
FIG. 8 is a flowchart showing an example of the power feeding process of the second example.
The process will be described with reference to FIG. 8. First, the control unit 104 of the power supply apparatus 100, which is a primary device, starts supplying the transmission power from the power transmission driver 103 to the primary coil 106 (step S21). At this time, as in the process of step S11 of the flowchart of FIG. 7, relatively low power for startup is set.

By starting the power transmission in this manner, the communication unit 206 and the control unit 205 of the terminal device 200, which is the secondary device, are activated (step S22).

Then, when the secondary device is activated, the control unit 205 of the terminal device 200 transmits a signal for confirming the transmission power of the power supply apparatus 100 from the communication unit 206 (step S23). When the communication unit 107 of the power supply apparatus 100 receives the signal for confirming the transmission power, the control unit 104 returns information indicating the transmission power from the communication unit 107, and the control unit 205 of the terminal device 200 transmits the information from the transmitted information. Check the transmission power.

Then, the control unit 205 determines the load power corresponding to the confirmed transmission power (step S24). That is, the load power consumed by the load circuit 204 is determined within a range not exceeding the presented transmission power.
Then, the control unit 205 determines whether the determined load power is greater than or equal to the threshold THx or less than the threshold THx.
Here, when the load power is equal to or higher than the threshold value THx, the control unit 205 instructs to use the DC-DC converter 211 as the regulator 210 (step S25).
If the load power is less than the threshold THx, the control unit 205 instructs the regulator 210 to use the LDO 212 (step S26). Note that, also in the case of this example, the input voltage of the regulator 210 is appropriately set based on, for example, the transmission power. As an example, when it is desired to keep the current constant, the control unit 205 sets any one of the input voltages 5V, 10V, and 15V corresponding to the transmission power 5W, 10W, and 15W, as shown in FIG.

Then, the control unit 104 of the power supply apparatus 100 starts power supply with the transmission power notified in step S23 (step S27).
As described above, according to the process of the flowchart of FIG. 8, the regulator 210 performs the voltage conversion using the DC-DC converter 211 or the LDO 212, whichever is appropriate, according to the load power set in the terminal device 200. I will do it.

As shown in the flowcharts of FIGS. 7 and 8, which of DC-DC converter 211 and LDO 212 is used to perform voltage conversion is selected based on the transmitted power or the load power. Therefore, it is possible to perform efficient non-contact power feeding both during low power transmission and high power transmission, and to suppress heat generation of the secondary coil 201 during high power transmission.

[7. Modification of Power Supply Processing (Modification 1)]
FIG. 9 is a flowchart showing a modified example 1 of the power supply process.
In the flowcharts of FIGS. 7 and 8, the regulator 210 is set at the start of power supply. On the other hand, the first modification is an example in which the control unit 205 of the terminal device 200 sets the regulator 210 based on the temperature detected by the temperature sensor 207.

That is, first, the control unit 205 of the terminal device 200, assuming that the received power is less than the threshold value THx, instructs the regulator 210 to use the LDO 212 (step S31). Then, after the power supply apparatus 100 starts power transmission (step S32), the control unit 205 of the terminal device 200 receives power for a predetermined X seconds (step S33), and determines whether power supply is completed. Perform (step S34). The X seconds here is, for example, about 60 seconds.

When it is determined in step S34 that power supply has been completed, the control unit 205 performs processing for completing power reception (step S35).
Then, when it is determined in step S34 that the power supply is continuing, the control unit 205 determines whether or not the temperature detected by the temperature sensor 207 is equal to or higher than a predetermined threshold temperature α° C. (step S36). If it is determined that the temperature is not higher than α° C., the control unit 205 returns to the process of step S33.

When it is determined in step S36 that the temperature is higher than or equal to α° C., the control unit 205 instructs the regulator 210 to use the DC-DC converter 211 and changes the input voltage of the regulator 210 to a high voltage such as 10V. (Step S37). After changing the setting of the regulator 210, the control unit 205 determines whether or not the power to be supplied can be normally received (step S38), and if the determination is not successful, the control unit 205 is in an abnormal state. Then, the power supply process is stopped (step S39).

When it is determined in step S38 that power can be normally received, the control unit 205 receives power for a predetermined X seconds (step S40), and determines whether power supply is completed (step S41).

When determining in step S41 that power supply has been completed, the control unit 205 performs processing for completing power reception (step S42).
Then, when it is determined in step S41 that the power supply is continuing, the control unit 205 determines whether or not the temperature detected by the temperature sensor 207 is equal to or higher than a predetermined threshold temperature α° C. (step S43). If it is determined that the temperature is not higher than α° C., the control unit 205 returns to the process of step S40.
When it is determined in step S40 that the temperature is higher than or equal to α° C., the control unit 205 determines that there is an abnormal state and stops the power supply process (step S44).

As shown in the flowchart of FIG. 9, the control unit 205 determines the conversion method in the regulator 210 by determining whether the temperature near the secondary coil 201 is equal to or higher than a predetermined threshold temperature α° C. By doing so, an appropriate conversion method and input power can be set. That is, in a state where the secondary coil 201 hardly generates heat, the control unit 205 determines that proper non-contact power supply is being performed, and receives power under the condition initially set. Then, when the secondary coil 201 has generated heat to some extent, it is determined that the power supply is large, and the control unit 205 changes the conversion method and the input voltage, so that the power can be properly received.

The process shown in the flowchart of FIG. 9 may be performed independently, but for example, the process at the start of power feeding shown in the flowchart of FIG. 7 or 8 is performed to start power feeding, and then the control unit 205. However, you may make it perform the process shown in the flowchart of this FIG.

[8. Modification of Power Supply Processing (Modification 2)]
FIG. 10 is a flowchart showing a modified example 2 of the power feeding process.
The second modification is an example in which the control unit 205 of the terminal device 200 determines the power reception efficiency of the power supply and sets the regulator 210.

That is, first, the control unit 205 of the terminal device 200 instructs the regulator 210 to select either the DC-DC converter 211 or the LDO 212 to perform the conversion operation (step S51). Then, after the power supply apparatus 100 starts power transmission (step S52), the control unit 205 of the terminal device 200 performs power reception for a predetermined X seconds (step S53), and the power reception efficiency of the current power supply is determined in advance. It is determined whether or not it is equal to or more than the determined β% (step S54). The power reception efficiency is calculated by the control unit 205. For example, the control unit 205 acquires information on the transmitted power from the power supply apparatus 100, further measures the power received by the terminal device 200, and the control unit 205 uses the received power and the supplied power. The power reception efficiency is obtained by calculation.

When determining in step S54 that the power reception efficiency is not β% or more, the control unit 205 gives an instruction to switch the conversion method of the regulator 210 to another method (step S55). At this time, if it is necessary to set the input voltage, the input voltage is also switched.
Then, it is determined whether power supply is completed (step S56). When it is determined in step S56 that power supply has been completed, the control unit 205 performs processing for completing power reception (step S57).
Then, when it is determined in step S56 that the power supply continues, the control unit 205 receives power for a predetermined X seconds (step S58), and the current power reception efficiency of the power supply is determined to be a predetermined β%. It is determined whether or not this is the case (step S59).

Here, when it is determined that the power receiving efficiency is β% or more, the control unit 205 returns to the process of step S58.
Further, when it is determined in step S59 that the power reception efficiency is not β% or more, the control unit 205 determines that the power cannot be received in a proper state regardless of the setting of the regulator 210, and the power supply is terminated. Is performed (step S60).

As shown in the flowchart of FIG. 10, the control unit 205 switches the conversion method in the regulator 210 based on the actual power reception efficiency, so that an appropriate conversion method and input power can be set.

Although the process shown in the flowchart of FIG. 10 may be performed independently, for example, the control unit 205 performs the process at the time of starting the power supply shown in the flowchart of FIG. 7 or 8 and starts the power supply. The processing shown in the flowchart of FIG. 10 may be performed.
Alternatively, the control unit 205 may use both the temperature-based selection process shown in the flowchart of FIG. 9 and the efficiency-based selection process shown in the flowchart of FIG.

[9. Other modifications]
In the example of the above-described embodiment, the regulator 210 includes the DC-DC converter 211 and the LDO 212. On the other hand, two other types of regulators having different conversion methods may be provided, and the two types of regulators may be switched based on transmitted power, load power, or the like.
Further, in the above-described embodiment, the example in which the power supply power is changed in three stages as shown in FIG. 2 has been shown. On the other hand, the supplied power may be changed in two steps or four or more steps. The relationship between the power supply power and the voltage or current shown in FIG. 2 is an example, and other power supply power, voltage, or current may be set.

In addition, in the example of the above-described embodiment, the information about the transmission power is transmitted from the power supply apparatus 100 to the terminal apparatus 200. On the other hand, instead of the transmitted power, the information indicating the conversion method of the regulator or the input voltage may be transmitted.
In addition, in the example of the above-described embodiment, the communication unit 107 of the power supply apparatus 100 and the communication unit 206 of the terminal device 200 are configured to perform communication by superimposing the transmission signal on the power supply power. On the other hand, communication may be performed using a wireless transmission line or a wired transmission line different from the system for supplying electric power.

Note that the present disclosure can also take the following configurations.
(1)
A power feeding device and a power receiving device that receives power from the power feeding device,
The power supply device,
Primary coil,
A driver for supplying transmission power to the primary coil,
A primary side control unit that controls the transmission power supplied by the driver in multiple stages;
A primary side communication unit that communicates with a side that receives electric power supplied from the primary side coil;
The power receiving device,
A secondary coil for receiving electric power sent from the primary coil;
A rectifying unit that rectifies the received power obtained in the secondary coil,
A regulator that converts the received power rectified by the rectifying unit into electric power of a predetermined voltage, and performs the conversion operation by a plurality of methods,
A secondary communication unit that communicates with the primary communication unit;
A non-contact power feeding system comprising: a secondary side control unit that controls a method of a voltage transformation operation performed by the regulator based on information received by the secondary side communication unit from the primary side communication unit.
(2)
When the information on the transmission power determined by the primary-side control unit is transmitted from the primary-side communication unit to the secondary-side communication unit, the secondary-side control unit performs the conversion operation method performed by the regulator. Is determined to be a method suitable for the transmitted transmission power.
(3)
The communication between the primary-side communication unit and the secondary-side communication unit is communication in which a transmission signal is superimposed on electric power transmitted from the primary-side coil to the secondary-side coil,
After transmitting power transmission power information from the primary side communication unit to the secondary side communication unit while performing power transmission from the primary side coil to the secondary side coil with a small amount of power for startup, The non-contact power supply system according to (1) or (2), wherein the primary side control unit sets the transmission power indicated by the information on the transmission power.
(4)
The said primary side control part determines transmission power based on the information transmitted to the said primary side communication part from the said secondary side communication part. Any one of said (1)-(3). Contactless power supply system.
(5)
The communication between the primary-side communication unit and the secondary-side communication unit is communication in which a transmission signal is superimposed on electric power transmitted from the primary-side coil to the secondary-side coil,
After transmitting power information from the secondary side communication unit to the primary side communication unit while performing power transmission from the primary side coil to the secondary side coil with a small amount of power for startup, The non-contact power supply system according to (1) or (2), wherein the secondary-side control unit sets the transmission power indicated by the load power information.
(6)
The secondary-side control unit determines load power based on information transmitted from the secondary-side communication unit to the primary-side communication unit. Any one of (1), (2), and (5) above. The contactless power supply system according to item 1.
(7)
The power receiving device includes a temperature sensor that detects a temperature in the vicinity of the secondary coil,
The non-contact power supply system according to any one of (1) to (6), wherein the secondary side control unit controls a method of a voltage transforming operation performed by the regulator based on a temperature detected by the temperature sensor. ..
(8)
The non-contact power supply system according to any one of (1) to (7), wherein the secondary-side control unit controls a method of a voltage transformation operation performed by the regulator, based on efficiency of receiving transmitted power.
(9)
The contactless power supply system according to any one of (1) to (8), wherein the regulator includes two regulators of a series regulator and a switching regulator.
(10)
A secondary coil for receiving the electric power sent from the primary coil of the power feeding device;
A rectifying unit that rectifies the received power obtained in the secondary coil,
A regulator that converts the received power rectified by the rectifying unit into electric power of a predetermined voltage, and performs the conversion operation by a plurality of methods,
A communication unit that communicates with the power supply device;
A terminal device, comprising: a control unit that controls a method of a voltage transformation operation performed by the regulator based on information received by the communication unit.
(11)
When the information of the transmission power determined by the power feeding device is transmitted to the communication unit, the control unit determines a conversion operation method performed by the regulator to a method suitable for the transmitted transmission power. (10) The terminal device as described above.
(12)
The communication in the communication unit is communication in which a transmission signal is superimposed on electric power transmitted from the primary coil to the secondary coil,
The terminal device according to (10) or (11), wherein the power supply device is notified of load power by communication by the communication unit.
(13)
A temperature sensor for detecting the temperature in the vicinity of the secondary coil,
The said control part is a terminal device as described in any one of said (10)-(12) which controls the system of the transformation|conversion operation which the said regulator performs based on the temperature which the said temperature sensor detected.
(14)
The said control part is a terminal device as described in any one of said (10)-(13) which controls the system of the transformation|transformation operation|movement which the said regulator performs based on the efficiency which receives transmitted power.
(15)
The terminal device according to any one of (10) to (14), wherein the regulator includes two regulators of a series regulator and a switching regulator.
(16)
Primary coil,
A driver for supplying transmission power to the primary coil,
A communication unit that communicates with a device on the side that receives power supplied from the primary coil;
A contactless power supply device comprising: a control unit that controls the transmission power supplied to the primary coil by the driver in a plurality of stages, and determines a transmission power based on information received by the communication unit.
(17)
The communication by the communication unit is communication in which a transmission signal is superimposed on the electric power transmitted from the primary coil,
After transmitting the information on the transmitted power from the communication unit while performing the power transmission from the primary coil with a small amount of power for startup, the control unit controls the transmitted power indicated by the information on the transmitted power. The contactless power supply device according to (16), wherein the setting is performed.
(18)
When performing non-contact power feeding from a power feeding device having a primary coil to a power receiving device having a secondary coil,
A regulator for converting the electric power received by the secondary coil into electric power of a predetermined voltage is operated by a plurality of conversion operations,
A contactless power feeding method for setting a method of a voltage transformation operation performed by the regulator, based on information obtained by communication between the power feeding device and the power receiving device.

Furthermore, the configurations and processes described in the claims of the present invention are not limited to the examples of the above-described embodiments. It will be understood by those skilled in the art that various modifications, combinations, and other embodiments can be made without departing from the scope of the present invention.

10... Power feeding device, 11... AC power supply, 12... AC/DC converter, 13... Power transmission driver, 14... Capacitor, 15... Primary coil, 20... Terminal device, 21... Secondary coil, 22... Capacitor, 23 ... rectifying section, 24... regulator, 25... charging control section, 26... secondary battery, 100... power supply apparatus, 101... AC power supply, 102... AC/DC converter, 103... power transmission driver, 104... primary side control section, 105... Capacitor, 106... Primary coil, 107... Primary communication section, 200... Terminal device, 201... Secondary coil, 202... Capacitor, 203... Rectifier section, 204... Load circuit, 205... Secondary side Control unit, 206... Secondary communication unit, 207... Temperature sensor, 210... Regulator, 211... DC-DC converter, 212... LDO

Claims (6)

A power receiving unit that receives the power sent from the power feeding device in a contactless manner,
A rectifying unit that obtains a voltage by rectifying the received power obtained by the power receiving unit,
A regulator that converts the voltage output from the rectification unit into a predetermined voltage using the first processing unit or the second processing unit;
A control unit that calculates a power reception efficiency of the power supplied from the power supply device;
The control unit adjusts the voltage output from the rectification unit by the first processing unit in the regulator, the second processing unit, or stops the regulator based on the power reception efficiency. Control what you do,
Terminal device. When the control unit selects either the first processing unit or the second processing unit and determines that the power reception efficiency is not equal to or higher than a predetermined threshold value after a predetermined time has passed, The terminal device according to claim 1, wherein the other of the first processing unit and the second processing unit is selected. The terminal device according to claim 2, wherein the control unit stops the regulator when it is determined that the power reception efficiency is still equal to or higher than the predetermined threshold value after a predetermined time has elapsed. The terminal device according to claim 1, wherein the first processing unit and the second processing unit are connected in series or in parallel. The terminal device according to claim 1, wherein the first processing unit is an LDO processing unit, and the second processing unit is a DC-DC converter processing unit. The terminal device according to claim 1, further comprising a temperature extraction unit that extracts a temperature in the vicinity of the power reception unit.

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