JP5518221B2 - Power transmitter - Google Patents

Description

The present invention relates to a technique for providing a non-contact power transmission device using a magnetic resonance phenomenon.

Currently, contactless power transmission technology is actively used in contactless IC cards, stationary handsets, and the like. Since electromagnetic induction is used for these non-contact power transmissions, the transmitted power and the received power are AC signals.

For this reason, in order to perform efficient power transmission, it is important that the resonance frequency on the power transmission side matches the resonance frequency on the power reception side.

Including these, non-contact power transmission is disclosed in Patent Documents 1 to 3 and Non-Patent Document 1.

JP-A-11-188113 JP-A-8-340285 JP 2000-99655 A

Andre Kurs, et al. “Wireless Power Transfer via Strongly Coupled Magnetic Resonances,” SCIENCE, VOL 317, pp.83-85, 6 JULY 2007

First, in Patent Document 1, the voltage level in the receiving coil is detected, and the resonance state of the transmitting coil and the receiving coil is controlled so that the detected voltage level always takes the maximum value.

In non-contact power transmission, the power receiving side is not always in an ideal position or state. When the position on the power receiving side is inappropriate or there is a problem with the state, there is a danger such as heating of the device.

In Patent Document 2, when the value of the sneak component of the transmission power exceeds a specified value, or when data reception from the power reception side cannot be detected by the data detection circuit, the power supply circuit 25
The transmission power is controlled by lowering the output voltage.

Further, as in Patent Document 3, there is a technique that enables non-contact communication simultaneously even with a plurality of IC cards having different antenna coils. However, in non-contact power transmission using electromagnetic induction, the power transmission distance is limited to a range of several millimeters to several centimeters, so there is a situation where power is transmitted to a plurality of power receivers at the same time. It is not done.

While the above technique performs non-contact power transmission by electromagnetic induction, a technique for performing non-contact power transmission using a magnetic resonance phenomenon as in Non-Patent Document 1 has been demonstrated. In non-contact power transmission using a magnetic resonance phenomenon, power transmission is possible even if the distance between the power receiving side and the power transmitting side is several meters.

The contactless power transmission handled in the present invention uses a magnetic resonance phenomenon, and the situation is different from that using electromagnetic induction handled in the prior art. First, the magnetic resonance phenomenon is the same as electromagnetic induction in that efficient power transmission can be performed when the resonance frequency of the power transmission device matches the frequency of the power reception device.

However, the resonance frequency band of power transmission due to the magnetic resonance phenomenon is narrow, and power cannot be transmitted even if the value of the resonant element is slightly shifted. For this reason, the resonance frequency in the power transmission device and the power reception device must be accurately matched.

However, since the resonance frequency band is narrow, the method of adjusting the resonance frequency by changing the resonance frequency makes it difficult to accurately adjust the resonance frequency because the voltage cannot be detected if the frequency is slightly shifted.

Next, if there is an object in the vicinity that has the same resonance characteristics as the receiving coil in the magnetic resonance phenomenon, power is also transmitted to the object, causing the object to be overheated or wasting power It is necessary to consider the possibility that a problem will occur.

In addition, when a problem occurs in the power transmission device or the power reception device, it is necessary to consider the possibility that the power is not transmitted and the device is overheated. When it is assumed that power is transmitted with a large amount of power, a mechanism with higher safety should be provided for these problems.

Furthermore, since the power transmission at a distance of several meters is possible when the magnetic resonance phenomenon is used, by using another power reception side having a reception resonance system having the same characteristics as the intended power reception side, There is a problem that can be stolen.

As described above, when the magnetic resonance phenomenon is used, it is possible to transmit several meters of power. Therefore, it is possible to use the power simultaneously by transmitting power to a plurality of power receiving sides.

When transmitting power to a plurality of power reception sides with the same resonance frequency on the power reception side, since the resonance frequencies are equal, transmission control can be individually performed for each power reception side. There is a problem that you can not.

In the device for transmitting power according to the present invention, the power receiving device is provided with a Q control circuit for changing the Q of the power receiving coil in order to change the resonance characteristic of the power receiving device, and the resonance frequency of the power receiving device. A resonance frequency control circuit for controlling, a reception power detection circuit for measuring received power, and a control unit for controlling the Q control circuit and the resonance frequency control circuit from values measured by the reception power detection circuit ing.

The control unit controls the Q control circuit to change the resonance frequency band, and the control unit controls the resonance frequency control circuit so that the received power becomes maximum.

In the apparatus for transmitting power of the present invention, the power receiving apparatus includes a received power detection circuit and a data transmission circuit that transmits a measurement value by the received power detection circuit to the power transmission apparatus.
A data reception circuit for receiving data of the reception power value measured by the reception power detection circuit, a transmission power detection circuit for measuring transmission power, and a reception power value and transmission power detection output from the data reception circuit A transmission / reception power comparison circuit for comparing transmission power values measured by the circuit, a power control circuit for controlling power to be transmitted according to a comparison result in the transmission / reception comparison circuit, and a storage unit for storing at least two transmission power setting values And a warning LED for notifying the user of a warning based on the comparison result in the transmission / reception comparison circuit.

The transmission / reception power comparison circuit outputs a difference between the reception power measured by the reception power detection circuit and the transmission power measured by the transmission power measurement circuit.

The transmission power control circuit uses a predetermined value or a value stored in the storage unit as a threshold value,
The transmission power is controlled by the value output from the transmission / reception power comparison circuit.

When there are a plurality of power receiving apparatuses, the power transmission apparatus according to the present invention has different resonance frequencies, and each power receiving apparatus has a power switch, and data transmission that sends the power switch status to the power transmitting apparatus as data. A data receiving circuit for receiving the state of the power switch of each power receiving device as data, a resonance frequency control circuit for controlling the resonance frequency of the power transmitting device, and controlling the oscillation frequency. To determine the oscillation frequency and resonance frequency to be set for power transmission from the power switch state data of each power receiving device and the oscillation corresponding to the power receiving device in which the switch is turned on A frequency switching circuit that controls the frequency and the resonance frequency in a time-sharing manner by a resonance frequency control circuit and an oscillation frequency control circuit is provided.

  Moreover, the said structure is demonstrated in another expression below.

A power receiving coil that receives a power transmission signal that transmits power transmitted from a power transmitting device; a Q control unit that changes a Q value that is a Q value of the power receiving coil; and the power receiving coil. A reception resonance frequency control unit that controls the resonance frequency in the reception processing of the received signal, a reception power detection unit that detects a reception power value that is the power of the received power transmission signal, the Q control unit, and the reception resonance frequency control unit. And a control unit that controls the reception resonance frequency control so that the reception power value detected by the reception power detection unit becomes a resonance frequency that approaches a maximum with a predetermined Q value. After controlling the unit, the Q control circuit is controlled to increase the Q value.

A power transmission coil for transmitting a power transmission signal for transmitting power, a power control unit for controlling the power of the power transmission signal transmitted from the power transmission coil, and a power value of the transmitted power transmission signal. A transmission power detection unit that detects a transmission power value, a data reception unit that receives data indicating a reception power value that is a power value of a power transmission signal received by the power reception device, and the transmission power detection unit detects A power transmission unit comprising: a power comparison unit that outputs a comparison result obtained by comparing a transmission power value with a reception power value received by the data reception unit; and a storage unit that stores a transmission power setting value for setting the transmission power value. In the apparatus, when the received power value is smaller than a predetermined value with respect to the transmission power value from the comparison result output from the power comparison unit, the power control unit transmits a power transmission signal. Stop If the received power value is larger than a predetermined value with respect to the transmission power value based on the comparison result output from the power comparison unit, the transmission power is stored in the storage unit. The power transmission signal is transmitted by changing to a different transmission power setting value. Also, from the comparison result output from the power comparison unit, the reception power value is determined from a predetermined value with respect to the transmission power value. Is also set to a transmission power setting value that gradually increases, and the power control unit performs control to transmit the power transmission signal. Also, a display unit that displays an abnormality is provided, From the comparison result output from the power comparison unit, when the received power value is smaller than a predetermined value with respect to the transmission power value, the power control unit causes the display unit to display an abnormality. Try to control.

In addition, a power transmission coil that transmits a power transmission signal for transmitting power, a power control unit that controls the power of the power transmission signal transmitted from the power transmission coil, and reception of the power transmission signal by the power reception device A data reception unit that receives power reception state data indicating an operation state of the power, a transmission resonance frequency control unit that controls a resonance frequency of the power transmission signal, and frequency switching control to the transmission resonance frequency control unit, and the power In a power transmission device including a frequency switching unit that switches a resonance frequency of a transmission signal, time division is performed at a resonance frequency corresponding to the power reception device receiving power based on the power reception state data received by the data reception unit. As in
The transmission switching frequency control unit is controlled by the frequency switching unit.

According to the present invention, even in a transmission / reception system with a narrow resonance frequency band, the resonance frequency can be optimized more stably than before, and even when transmitting a large amount of power, a failure is detected at the low power transmission stage. It becomes possible to stop power transmission.

It is also possible to stop power transmission when a problem or power theft occurs during power transmission, and for each of the power receiving devices, the transmission power amount, oscillation frequency, and resonance frequency Control can be performed.

It is a block diagram which shows the structure of 1st Embodiment of this invention. It is a flowchart which shows operation | movement of 1st Embodiment of this invention. It is a block diagram which shows the structure of 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of 2nd Embodiment of this invention. It is a block diagram which shows the structure of 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of 3rd Embodiment of this invention. It is a block diagram which shows the structure of 4th Embodiment of this invention. It is a block diagram which shows the structure of 5th Embodiment of this invention. It is the table | surface which showed the example of the transmission power value in the 1st Embodiment of this invention for every step of transmission power amount, and the threshold value of a power transmission stop.

  Embodiments of the present invention will be described below with reference to the drawings.

A non-contact power transmission apparatus according to a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the overall configuration of an apparatus for transmitting non-contact power using a magnetic resonance phenomenon.

Reference numeral 1 denotes a power transmission device, which uses an AC power source A, a power source circuit 10 that generates a power source for driving each circuit from the AC power source, and a Corbitz oscillator that oscillates a power transmission signal for transmitting power at a desired frequency. The oscillation circuit 11, the power transmission coil 13 for transmitting the power transmission signal, the coil 12 for exciting the power transmission coil 13, the resonance frequency control circuit 14 for controlling the transmission resonance frequency, and the Q of the transmission coil A Q control circuit 15 for controlling the frequency, an oscillation frequency control circuit 16 for controlling the frequency of the oscillation circuit, and a data reception circuit 17 for receiving control data.

Reference numeral 2 denotes a power receiver, a power receiving coil 21 for receiving a power transmission signal, a coupling coil 23 with the power receiving coil 21, a Q control circuit 22 for changing the Q of the power receiving coil, and reception The resonance frequency control circuit 24 for controlling the resonance frequency, the power detection circuit 25 for measuring and detecting the received power, and the value of the reception resonance frequency and the reception coil according to the value measured and detected by the power detection circuit 25 The control unit 26 that controls the Q value, the oscillation frequency of the power transmission device, the transmission resonance frequency, and the Q value of the transmission coil, and the load 2 that consumes the received power
7. Data transmission circuit 28 that transmits control information to the power transmission device using a communication method such as Bluetooth, for example, secondary battery 210 that supplies power for driving each circuit on the power reception side, and secondary battery 210 It consists of a charging circuit 29 that performs charging.

In the non-contact power transmission apparatus according to the embodiment of the present invention, the Q of the reception coil of the power reception apparatus and the reception resonance frequency are controlled so that the transmission frequency of the power transmission signal matches the reception resonance frequency. The operation in this case is shown in the flowchart of FIG.

First, in the power receiving device 2, the control unit 26 controls the Q control circuit 22 as an initial state to set the Q of the power receiving coil to a high value and set the Q of the power receiving coil to be low (S11). ). By setting Q low, the resonance frequency band on the receiving side is widened.

Next, power is oscillated from the oscillation circuit 11 at a predetermined frequency. The oscillated power is transmitted from the power transmission coil 13 through the excitation coil 12. The transmitted power is received by the power receiving device by the coupling coil 23 through the power receiving coil 21 (
S12).

In the control unit 26, for example, the resonance frequency control circuit 24 composed of a variable capacitor is controlled to increase the reception resonance frequency, and a frequency having the highest power measured by the power detection circuit 25 is searched (S13, S14).

Next, the resonance frequency control circuit 24 is controlled, and conversely, the reception resonance frequency is lowered to search for a frequency having the highest power measured by the power detection circuit 25 (S15, S16, S17).

The frequency of the power transmitted by the series of operations can be matched with the power reception resonance frequency. If the Q control circuit 22 does not reach the specified value after matching the resonance frequency, the Q control circuit 22 is operated from the control unit 26 to increase the Q of the power receiving coil, and the resonance frequency characteristic on the receiving side Is sharpened (S18, S19).

Thereafter, the operation of matching the transmission power frequency and the power reception resonance frequency again is performed by the Q control circuit 2.
Repeat until 2 reaches the specified value. Note that the power used to drive the detection circuit, the data transmission circuit, and each control circuit may be the received power or the power obtained from the secondary battery 210 provided. .

When a secondary battery is used, charging is performed by the charging circuit 29 using the received power. If a secondary battery is used, even if the amount of received power is insufficient to drive the circuit,
The circuit can be driven stably.

This is the description of the operation of the non-contact power transmission apparatus according to the embodiment of the present invention. As described above, it is not a method in which the Q of the power receiving coil is first lowered and gradually increased while the Q is gradually increased. It is conceivable to perform the adjustment.

However, when Q is high from the beginning, the resonance frequency band becomes narrow, and if the resonance frequency slightly deviates from the power transmission frequency, power cannot be detected. The fact that electric power cannot be detected with a slight frequency shift means that it is difficult to obtain a clue to adjust the resonance frequency, and the operation for adjusting the resonance frequency cannot be performed well. .

Therefore, in the embodiment of the present invention, the operation of adjusting the resonance frequency from the state where the Q of the receiving coil is lowered, that is, the state where the resonance frequency band is widened, is performed stably. It is effective in that it can be performed.

In the above embodiment, the transmission / reception resonance frequency is adjusted by controlling the Q of the reception coil of the power reception device and the reception resonance frequency and matching the transmission power frequency and the power reception resonance frequency. The transmission-side Q control circuit 15, oscillation frequency control circuit 16, and resonance frequency control circuit 14 may be controlled to adjust the oscillation frequency and the transmission / reception resonance frequency.

An apparatus for transmitting non-contact power according to a second embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a diagram illustrating an example of the overall configuration of a device that transmits electric power without contact. 3
Is a power transmission device, an oscillation circuit 11 that generates power to be transmitted at a desired frequency, a power transmission coil 13 for transmitting power, an excitation coil 12 for exciting the power transmission coil 13, and transmission A transmission power detection circuit 31 that measures a transmission power value that is a power value of the power transmission signal to be received, and for receiving data indicating a reception power value that is a power value of the power transmission signal received from the power receiving device through communication Data reception circuit 33, transmission / reception power comparison circuit 32 for outputting the difference between the received power value on the power reception side received as data and the transmission power value measured by transmission power detection circuit 31, and oscillation from the output difference value The power control circuit 34 for determining and controlling the frequency, the magnitude of power, etc. of the power transmission signal oscillated by the circuit 11, and the setting values set in the power control circuit are stored. Ku made from the storage unit 35. It is assumed that the power source of the power transmission device is supplied to each circuit from the AC power source through the power source circuit as in the first embodiment.

Reference numeral 4 denotes a power receiving device, which includes a power receiving coil 21 for receiving power, a coupling coil 23 with the power receiving coil 21, and power detection using, for example, a diode detection method for measuring the received power. The circuit 25 includes a data transmission circuit 41 that transmits the reception power measured by the power detection circuit 25 as data to the reception side, and a load 27 that consumes the received power.

The operation of the non-contact power transmission apparatus according to the embodiment of the present invention is shown in the flowchart of FIG.

First, the power control circuit 34 causes the oscillation circuit 11 set in the storage unit 35 to oscillate at a low power with a value smaller than the power to be finally transmitted (S201). For example, FIG.
As shown in the example of the contents of the storage unit 35, 10% of the power to be finally transmitted is oscillated. The oscillated power is transmitted by exciting the power transmission coil 13 by the excitation coil 12.

The power is received by the power receiving coil 21 and is sent to the receiving circuit through the coupling coil 23 (S202).

The power received on the power reception side is measured by the power detection circuit 25, and the value is transmitted to the power transmission side by the data transmission circuit 41 (S210, S211 and S212).

The power used for driving the detection circuit and the data transmission circuit may be the power received in the same manner as in the first embodiment, or may be the power obtained from a secondary battery provided. .

If a secondary battery is used, the circuit can be driven stably even when the amount of received power is insufficient to drive the circuit. On the power transmission side, the data reception circuit 33 receives the received power value transmitted from the reception side (S203).

When the difference between the received value and the power value measured by the transmission power detection circuit 31 is output by the transmission / reception power comparison circuit 32 and the difference is larger than a preset threshold value, for example, the value shown in FIG. When the reception power value received on the reception side is smaller than the transmission power value transmitted on the reception side, the power control circuit 34 immediately stops the oscillation of power in the oscillation circuit (S204, S2).
05, S206-NO, S208). In this case, the transmission power is sufficiently high because, for example, an object exists between the power transmission device and the power reception device, even though power is transmitted from the power transmission device by the power transmission signal. It is assumed that it has not been transmitted. Therefore, if the received power value is increased and the transmitted power value is increased, power may be supplied to the above-mentioned object or the like, and in some cases, it may be dangerous due to abnormal heating or the like. obtain. Therefore, as described above, when the reception power value is smaller than the threshold value with respect to the transmission power value, the transmission of the power transmission signal from the power transmission device is stopped.

When the difference between the received power value, which is the received value, and the transmitted power value is within the threshold value, and the oscillation power has not reached the power to be finally transmitted, the power control circuit 32 stores it in the storage unit. The power that is one step larger than the currently transmitted power is transmitted, and the process returns to the received power detection operation again (S206—YES, S207, S209).

For example, when the transmission power is in the first stage in FIG. 9, the transmission power is switched to the second stage. When the oscillation power has reached the power to be finally transmitted stored in the storage unit, for example, in the case of the fourth stage in FIG. 9, the process is terminated.

Note that the transmission power may be switched by using a method in which the transmission power is increased by a fixed step amount in addition to using the value stored in the storage unit.

This is the description of the operation of the apparatus according to the embodiment of the present invention. As described above, a method of transmitting specified transmission power from the beginning without using a method of increasing transmission power in stages while confirming the power value received on the receiving side can be considered.

In the device for transmitting non-contact power using the magnetic resonance phenomenon handled in the embodiment of the present invention, when an object having a resonance characteristic equivalent to that of the receiving coil is in the vicinity, the power is also transmitted to the object. Thus, there may be a problem that the object is overheated or wasteful power consumption occurs.

Considering the occurrence of such problems, it is necessary to consider the danger that if the specified power is transmitted from the beginning, the transmission power may cause serious damage.

On the other hand, if the method shown in the embodiment of the present invention is used, it is possible to detect power failure and stop power transmission at the low power transmission stage. Even if the failure detection is delayed, the transmission can be performed at a low power in the initial stage, so that damage can be minimized.

A non-contact power transmission apparatus according to a third embodiment of the present invention will be described with reference to the drawings.

  FIG. 5 is a diagram showing an example of the overall configuration of an apparatus for transmitting power without contact.

Reference numeral 5 denotes a power transmission device including an alarm LED 51 controlled by a transmission power control circuit, and other configurations are the same as those of the power transmission device 3 shown in FIG.

It is assumed that the power source of the power transmission device is supplied to each circuit from the AC power source through the power source circuit as in the first embodiment. Reference numeral 6 denotes a power receiver, and the configuration thereof is the power receiver 4 shown in FIG.
It is the same.

The operation of the non-contact power transmission apparatus according to the embodiment of the present invention is shown in the flowchart of FIG.

First, power is oscillated from the oscillation circuit 11 at a predetermined frequency (S301).
. The oscillated power is transmitted from the power transmission coil 13 through the excitation coil 12.

The transmitted power is received by the power receiving device through the power receiving coil 21 and by the coupling coil 23 (S307).

The power value received by the power reception device is measured by the reception power detection circuit 25, and the value is sent to the power transmission device by the data transmission circuit 41 (S308, S309).

The power used for driving the detection circuit and the data transmission circuit may be the power received in the same manner as in the first embodiment, or may be the power obtained from a secondary battery provided. .

If a secondary battery is used, the circuit can be driven stably even when the amount of received power is insufficient to drive the circuit.

  The transmitted data is received by the data reception circuit 33 of the power transmission device (S302).

The transmission power detection circuit 31 measures the power value transmitted by the power transmission apparatus, and the transmission / reception power comparison circuit 32 compares the transmitted power value with the power value actually received by the power reception apparatus ( S303, S304).

If the difference between the compared power values is greater than or equal to a predetermined threshold value, the power control circuit 3
4 judges that there is something wrong, controls and stops power transmission, and alarm LED
51 is turned on to notify the user of the trouble (S305, S306, S307).

If the difference between the compared power values is within a predetermined threshold value, power transmission is continued as it is. This series of operations is performed at regular time intervals to monitor the received power.

This is the description of the operation of the apparatus according to the embodiment of the present invention. When the above operation is not performed, if an object having resonance characteristics equivalent to that of the receiving coil appears during power transmission, power is also transmitted to the object and the object is overheated. And a problem that wasteful power consumption occurs.

Further, when a circuit on the power receiving side fails and power cannot be received, there is a risk that the power transmitting coil, the circuit on the power receiving side, and the like are overheated. Furthermore, there is a possibility that the power is stolen by using another power receiving side having a reception resonance system having the same characteristics as the intended power receiving side. From the above, it can be said that the apparatus according to the embodiment of the present invention is effective.

A non-contact power transmission apparatus according to a fourth embodiment of the present invention will be described with reference to the drawings.

  FIG. 7 is a diagram illustrating an example of the overall configuration of a device that transmits electric power without contact.

Reference numeral 7 denotes a power transmission device, an oscillation circuit 11 for oscillating transmission power at a desired frequency, a power transmission coil 13 for transmitting power, and a coil 1 for exciting the power transmission coil 13.
2, a resonance frequency control circuit 71 that controls the resonance frequency of the power transmission coil, an oscillation frequency control circuit 74 that controls the oscillation frequency of the oscillation circuit 11, a reception circuit 72 that receives data transmitted from the power reception side, The frequency switching circuit 73 controls the frequency of the transmission frequency control circuit and the resonance frequency control circuit in consideration of data information.

It is assumed that the power source of the power transmission device is supplied to each circuit from the AC power source through the power source circuit as in the first embodiment.

Reference numerals 81, 82, and 83 denote a plurality of power receiving apparatuses, which are coupling coils 812, 822, and power receiving coils 811, 821, 831, and power receiving coils 811, 821, 831, respectively, for receiving power. 832, loads 815, 825, and 835 that consume electric power, and power switches 813 and 8 for electrically connecting and disconnecting the load and the coupling coil
23, 833, transmission circuits 814, 824, 8 for transmitting the state of the power switch as data
34. In FIG. 7, the number of power receiving apparatuses is three.

  The operation of the non-contact power transmission apparatus according to the embodiment of the present invention is described.

The characteristics are determined so that the resonance frequencies of the power receiving coils 811, 821, and 831 and the coupling coils 812, 822, and 832 are unique to each power receiving apparatus.

In addition, the resonance frequency control circuit 71 and the oscillation frequency control circuit 74 can control the frequency of the oscillation circuit and the transmission resonance frequency so as to oscillate or resonate at the resonance frequency of each power receiving device 81, 82, 83. .

First, each power receiving apparatus transmits the states of the power switches 813, 823, and 833 through the data transmission circuit. The power transmission apparatus acquires the data by the reception circuit 72.

At this time, the power used for driving the detection circuit and the data transmission circuit in the power source of each power receiving device may be the same as that received in the first embodiment, or may be provided with a secondary battery. You may use the electric power obtained from.

If a secondary battery is used, the circuit can be driven stably even when the amount of received power is insufficient to drive the circuit. When the power transmitted from the power transmission device is used, the power is periodically transmitted to the full power reception device.

Such power transmission is not necessary when using a secondary battery. The power transmission device receives the power switch states 813, 823, and 833 of each power reception device by the data reception circuit 72, and then sets an oscillation frequency and a resonance frequency corresponding to the reception resonance frequency of the power reception device in which the power switch is turned on. The oscillation frequency control circuit 74 and the resonance frequency control circuit 71 are controlled and switched in a time division manner.

The frequency of the oscillation circuit and the resonance frequency of the power transmission device change with the control of the oscillation frequency control circuit 74 and the resonance frequency control circuit 71, and the power is transmitted from the power transmission coil 13 through the excitation coil 12.

Since power having a frequency corresponding to the resonance frequency of the receiving device is transmitted to the power receiving device that is turned on, the receiving coils 811, 821, and 831 are coupled to the coupling coils 812 and 822.
, 832, power is transferred to loads 815, 825, 835. From the above operation,
Only the power receiving apparatus including the power switches 813, 823, and 833 can selectively transmit power to a plurality of power receiving apparatuses.

This is the description of the operation of the apparatus according to the embodiment of the present invention. When transmitting power to a plurality of power receiving devices as described above, the resonance frequency of all the power receiving devices is set to the same frequency in addition to the method of transmitting the power of the frequency corresponding to each power receiving device in time division. A method of transmitting power to a plurality of power receiving devices by transmitting power at the frequency of the power transmitting device can be considered.

However, when power is transmitted and received at the same frequency, power is transmitted to a power receiving apparatus that is not turned on, resulting in waste. Further, it is impossible to individually control the transmission power amount, the oscillation frequency, and the resonance frequency for each power receiving apparatus. From the above points, the method of transmitting the power of the frequency corresponding to each power receiving apparatus by the time division described in the embodiment of the present invention is effective.

A non-contact power transmission apparatus according to a fifth embodiment of the present invention will be described with reference to the drawings.

FIG. 8 is a diagram showing an embodiment in which a device for transmitting non-contact power is applied to a television. This television is divided into a tuner unit and a monitor unit, and communication of video, audio, and control data between the tuner unit and the monitor unit is performed wirelessly.

Reference numeral 1000 denotes an AC power source, for example, a home AC power source, 1001 denotes a broadcast wave receiving antenna, 1002 denotes a video / audio signal source such as a VTR or a DVD player, and the like.
Reference numeral 3 denotes a tuner unit, and 1004 denotes a power transmission device, which corresponds to the configuration of the power transmission device 1 of the first embodiment, for example. 1006 denotes a power reception device, for example, the configuration of the power reception device 2 excluding the load 27 of the first embodiment 1005 is a monitor unit described later and broadcast is video and audio received by the receiving antenna 1003, or video and audio video data and audio data of the video / audio signal source 1002 and control data between the tuner unit monitor unit. Video, audio and control data communication unit for communication, 100
Reference numeral 7 denotes video, audio, and video data, audio data, and control data communicated with the tuner unit 1003.
A control data communication unit 1008 is a monitor unit that outputs video and audio.

The operation of the non-contact power transmission apparatus according to the embodiment of the present invention will be described. Power supply 100
0 is supplied to the power transmission apparatus 1004 through the tuner unit 1003. Power transmission device 10
04 transmits power to the power receiving apparatus 1006 in a contactless manner, for example, by the operation described in the first embodiment. The monitor unit 1008 functions as a load and corresponds to the load 27 in the first embodiment, for example.

In the first embodiment, the power transmission device and the power reception device are provided with the data reception unit and the data transmission unit, respectively. However, the video, audio, and control data communication units 1005 and 1007 store data in the power transmission device and the power reception device. You may handle sending and receiving. With such a configuration, the configuration of the power transmission device and the power reception device can be simplified.

If the non-contact power transmission device of the present invention is used in a television that wirelessly communicates video, audio, and control data between the tuner unit and the monitor unit, complete wireless communication between the tuner unit and the monitor unit is achieved. be able to.

In addition, although the Example of this invention was described above, as embodiment of this invention, it is not limited to description of said Example, You may combine the structure of each Example suitably. Is.

1, 3, 5, 7 power transmission device, 2, 4, 6, 81-83 power reception device, 10 power supply circuit, 1
1 oscillation circuit, 12 excitation coil, 13 power transmission coil, 21, 811, 821, 831
Coil for power reception, Q control circuit for Q change of 15, 22 coils, 23, 812, 822, 8
32 coupling coils, 24 power receiver resonance frequency control circuit, 25 reception power detection circuit, 26 resonance frequency and Q change control unit, 27, 815, 825, 835 load, 31 transmission power detection circuit, 32 transmission / reception power comparison circuit, 17 33, 72 data receiving circuit, 34 power control circuit, 3
5 storage units, 28, 41, 814, 824, 834 data transmission circuit, 51 alarm LED,
4, 71 power transmission device resonance frequency control circuit, 73 frequency switching circuit, 16, 74 oscillation frequency control circuit, 29 charging circuit, 2102, secondary battery, A, 1000 AC power supply, 1001 broadcast wave receiving antenna, 1002 video / audio signal source , 1003 tuner unit, 1004 power transmission device, 1
005, 1007 video, audio, control data communication unit, 1006 power receiver, 1008 monitor unit

Claims (2)

A power transmission coil for transmitting a power transmission signal for transmitting power;
A power control unit for controlling the power of the power transmission signal transmitted from the power transmission coil;
A transmission power detection unit that detects a transmission power value that is a power value of a transmitted power transmission signal;
A data receiving unit that receives data indicating a received power value, which is a power value of a power transmission signal received by the power receiving device;
A power comparison unit that outputs a comparison result comparing the transmission power value detected by the transmission power detection unit and the reception power value received by the data reception unit;
A storage unit for storing a transmission power setting value for setting a transmission power value;
In a power transmission device comprising:
The power control unit
From the comparison result output from the power comparison unit,
When the received power value is smaller than a predetermined value with respect to the transmission power value, control to stop transmission of the power transmission signal,
From the comparison result output from the power comparison unit,
When the received power value is larger than a predetermined value with respect to the transmission power value,
The power control unit performs control to read the transmission power setting value stored in the storage unit, change the transmission power setting value to a large value stepwise, and transmit the power transmission signal.
A power transmission apparatus characterized by that.   The power transmission device according to claim 1,
  Provide a display to display the abnormality,
  From the comparison result output from the power comparison unit,
When the received power value is smaller than a predetermined value with respect to the transmission power value, the power control unit controls the display unit to display an abnormality.
A power transmission apparatus characterized by that.

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