JP2013251955A - Power transportation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transport power from a power base to a portable device while transmitting an information signal stably and reliably from the portable device to the power base.SOLUTION: In the power transportation method, in a state where power is transported by magnetically coupling a power transmission coil 11 of a power base 10 and a power reception coil 51 of a portable device 50, the portable device 50 transmits an information signal to the power base 10 by a modulation system of changing the load impedance of the power reception coil 51, the power base 10 detects the information signal by detecting a change in the load impedance of the power reception coil 51 via the power transmission coil 11, and then the power base 10 transports power from the power transmission coil 11 to the power reception coil 51 while controlling the feed power of the power transmission coil 11 by the information signal transmitted from the portable device 50 side. Furthermore, the power base 10 transmits the information signal by setting the feed power of the power transmission coil 11 to a maximum initial power capable of transmitting the information signal from the portable device 50 to the power base 10, and then decreases the feed power of the power transmission coil 11 to an optimum feed power.

Description

  The present invention relates to a power transfer method in which a portable device is set on a power supply stand and power is transferred from a power transmission coil of the power supply stand to a power reception coil of the portable device.

A power transfer method has been developed in which a portable device is set on a power supply stand and power is transferred from a power transmission coil of the power supply stand to a power reception coil of the portable device. (See Patent Document 1)
This power transfer method can transfer power from a power supply stand to a portable device without contact. This method carries power while transmitting information signals from a portable device to a power supply stand. For example, a power signal is transmitted from a portable device to a power supply base by detecting power induced in the power receiving coil, or a signal indicating that a charged battery is fully charged. The power supply stand detects the power transmission efficiency from the ratio between the power signal transmitted from the portable device and the power supplied to the power transmission coil, and adjusts the power supplied to the power transmission coil so that the power transmission efficiency is in a preferable state. When detecting that the battery being charged is fully charged, the power supply to the power transmission coil is stopped and the charging is stopped.

  In order to transmit an information signal from a portable device to a power supply stand, the power transfer method of Patent Document 1 is provided with a capacitor 187 and a switching element 186 in parallel with a power receiving coil 151 on the portable device 150 side as shown in FIG. A modulation circuit 184 composed of a series circuit is connected. The modulation circuit 184 switches the FET of the switching element 186 on and off, modulates it with an information signal so as to change the load impedance of the power receiving coil 151, and transmits it to the power supply stand 110. The power supply stand 110 detects a change in load impedance of the power receiving coil 151 via the power transmission coil 111 to detect an information signal. When the load impedance of the power receiving coil 151 changes, the amplitude of the AC waveform of the power transmitting coil 111 that is electromagnetically coupled to the power receiving coil 151 changes. For example, when the load impedance of the power receiving coil 151 increases, the amplitude of the AC waveform of the power transmission coil 111 decreases, and when the load impedance of the power receiving coil 151 decreases, the amplitude of the AC waveform increases. For this reason, the AC waveform of the power transmission coil 111 is amplitude-modulated by the information signal of the portable device 150. Therefore, the power supply stand 110 can detect an information signal from the amplitude fluctuation of the AC waveform of the power transmission coil 111.

JP 2009-273327 A

  In the modulation method in which the load impedance of the power receiving coil is changed by the information signal, the power supply stand detects the information signal by detecting the AC waveform of the power transmitting coil. However, in this method, the change width of the AC waveform of the power transmission coil is reduced depending on the load on the portable device side. For this reason, when the load on the portable device increases, even if the load impedance of the power receiving coil is changed, the change in the load impedance cannot be detected by the power transmission coil. Therefore, there is a drawback that information signals cannot be stably transmitted from the portable device to the power supply stand. Since the power supply base detects an information signal transmitted from the portable device and controls the supply of AC power to the power transmission coil, if the information signal cannot be detected, power cannot be normally transferred from the power supply stand to the portable device.

  The present invention has been developed for the purpose of solving this drawback. An important object of the present invention is to provide a method capable of conveying power from a power supply base to a mobile device while stably and reliably transmitting an information signal even when the load of the mobile device fluctuates. It is in.

Means for Solving the Problems and Effects of the Invention

  In the power transfer method of the present invention, the portable device 50 is set on the power supply base 10, and the power transmission coil 11 of the power supply base 10 and the power reception coil 51 of the portable device 50 are electromagnetically coupled. While the power is being transferred to the power receiving coil 51 of the portable device 50 and the power is being transferred from the power transmission coil 11 of the portable device 50 to the power receiving coil 51, the power supply base 10 is modulated by the modulation method in which the portable device 50 changes the load impedance of the power receiving coil 51. The power supply base 10 detects a change in the load impedance of the power receiving coil 51 that is electromagnetically coupled to the power supply coil 11 via the power transmission coil 11 to detect the information signal. Power is conveyed from the power transmission coil 11 to the power reception coil 51 while controlling the power supplied to the power transmission coil 11 by the information signal transmitted from the 50 side. Further, in the power transfer method, the power supply base 10 transmits the information signal by setting the power supplied to the power transmission coil 11 to the maximum initial power that can transmit the information signal from the portable device 50 to the power supply base 10, and then the power transmission coil. 11 is reduced to the optimum supply power.

  The power transfer method described above is characterized in that power can be transferred from the power supply stand to the portable device while the information signal is stably and reliably transmitted from the portable device to the power supply stand even when the load of the portable device changes. This is because the above power transfer method transmits an information signal using the power supplied to the power transmission coil as the maximum initial power, and then reduces the power supplied to the power transmission coil to the optimum power. In a state where the load on the power receiving coil is large, for example, in a state where the charging current of the battery is large, the power supplied to the power transmitting coil can be increased to reliably detect a change in the load impedance of the power receiving coil. This is because when the power supplied to the coil is increased, the amplitude of the AC waveform is increased, and amplitude fluctuations can be reliably detected.

  FIG. 2 shows a state in which the amplitude of the AC waveform of the power transmission coil changes by changing the load impedance of the power reception coil in a state where the load of the power reception coil is large and the power supplied to the power transmission coil is small. As shown in this figure, when the load on the power receiving coil increases, the amplitude fluctuation of the AC waveform of the power transmission coil is extremely small, and the information signal cannot be accurately detected from the amplitude fluctuation. FIG. 3 shows a state in which the amplitude of the AC waveform of the power transmission coil changes while the load of the power receiving coil is increased in the same manner and the power supplied to the power transmission coil is increased. As shown in this figure, when the feeding power of the power transmission coil is increased, the amplitude fluctuation of the AC waveform of the power transmission coil is large even if the load of the power receiving coil is large, and the information signal can be reliably detected from the amplitude fluctuation.

  In the power transfer method of the present invention, the portable device 50 is set on the power supply base 10, and the power transmission coil 11 of the power supply base 10 and the power reception coil 51 of the portable device 50 are electromagnetically coupled. While the power is being transferred to the power receiving coil 51 of the portable device 50 and the power is being transferred from the power transmission coil 11 of the portable device 50 to the power receiving coil 51, the power supply base 10 is modulated by the modulation method in which the portable device 50 changes the load impedance of the power receiving coil 51. The power supply base 10 detects a change in the load impedance of the power receiving coil 51 that is electromagnetically coupled to the power supply coil 11 via the power transmission coil 11 to detect the information signal. Power is conveyed from the power transmission coil 11 to the power reception coil 51 while controlling the power supplied to the power transmission coil 11 by the information signal transmitted from the 50 side. Further, in the power transfer method, when the power supply stand 10 enters a non-detection state in which the information signal on the portable device 50 side cannot be detected, the power supply power of the power transmission coil 11 is increased to a level at which the information signal can be detected. An information signal is transmitted to the power supply base 10.

  The power transfer method described above is characterized in that power can be transferred from the power supply stand to the portable device while the information signal is stably and reliably transmitted from the portable device to the power supply stand even when the load of the portable device changes. This is because the above power transfer method increases the power supplied to the power transmission coil to a level at which the information signal can be detected and transmits the information signal from the portable device to the power supply base in a non-detection state where the information signal cannot be transmitted. .

  In the power transfer method of the present invention, the power supply base 10 stores the maximum power supply power of the power transmission coil 11 that can detect the information signal at the maximum load of the portable device 50, and the power supply base 10 cannot detect the information signal. The power supply base 10 can detect the information signal from the portable device 50 to the power supply base 10 by setting the power supply power of the power transmission coil 11 to the maximum power supply power.

  In the above power transfer method, the maximum power supply power stored in the power supply stand is supplied to the power transmission coil in the non-detection state of the information signal, so that the information signal can be stably transmitted from the portable device to the power supply stand. This is because the stored maximum power supply power can be set to a power that can reliably and stably transmit an information signal.

In the power transfer method of the present invention, the power supply stand 10 can detect a change in the load impedance of the power reception coil 51 from a change in the voltage amplitude of the power transmission coil 11 to detect an information signal.
The above power transfer method has a feature that an information signal can be detected from a change in voltage amplitude of a power transmission coil with a simple circuit configuration.

In the power transfer method of the present invention, the portable device 50 connects the series circuit 60 of the capacitor 61A and the switching element 62 in parallel with the power receiving coil 51, turns the switching element 62 on and off, and sets the load impedance of the power receiving coil 51. The information signal can be transmitted by changing.
In the above power transfer method, the load impedance of the power receiving coil is changed by switching between the state where the capacitor is connected to the power receiving coil and the state where the capacitor is not connected, so that the information signal can be transmitted stably without reducing the power transmission efficiency. There are features. This is because even if a capacitor is connected in parallel with the power receiving coil, the capacitor does not consume power.

In the power transfer method of the present invention, the portable device 50 can transmit the power induced in the power receiving coil 51 to the power supply base 10 as an information signal.
In this power transfer method, since the power induced in the receiving coil of the portable device is transmitted as an information signal to the power supply stand, the power supply stand detects the power transmission efficiency with the information signal transmitted from the portable device, and the power transmission efficiency There is a feature that can carry power while controlling the power to the optimum state.

It is a block diagram which shows the structure where the conventional electric power carrier apparatus transmits an information signal. It is a figure which shows the state from which the amplitude of the alternating current waveform of a power transmission coil changes by changing the load impedance of a power receiving coil in the state with small electric power feeding of a power transmission coil. It is a figure which shows the state which changes the amplitude of the alternating current waveform of a power transmission coil by changing the load impedance of a power reception coil in the state which increases the electric power feeding of a power transmission coil. It is a schematic block diagram which shows the power supply stand and portable apparatus which are used for the electric power conveyance method concerning one embodiment of this invention. It is a perspective view which shows an example of the power supply stand and portable apparatus which are shown in FIG. It is a graph which shows the state which adjusts the supply voltage of a power transmission coil and transmits an information signal from a portable apparatus to a power supply stand.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below exemplifies a power transfer method for embodying the technical idea of the present invention, and the present invention does not specify the power transfer method as the following method. Further, in this specification, in order to facilitate understanding of the scope of claims, numbers corresponding to the members shown in the examples are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

  In FIG. 4, the portable device 50 is a battery built-in device 50 </ b> A, the power supply base 10 is a charging base 10 </ b> A, power is transferred from the power transmission coil 11 to the power reception coil 51, and the battery 52 of the portable device 50 is charged. However, the present invention does not specify the power supply base of the power transfer method as a charging stand, and does not specify the portable device as a battery built-in device. This is because the portable device can be an illumination or a charging adapter provided with a light source, and power can be transferred to the portable device from the power supply stand.

  In FIG. 4, the portable device 50 is a battery built-in device 50 </ b> A that incorporates a battery 52, and the power supply base 10 is a charging stand 10 </ b> A that charges the battery 52 of the battery built-in device 50 </ b> A. The portable device 50 charges the battery 52 with the power receiving coil 51 that is electromagnetically coupled to the power transmitting coil 11 of the power supply base 10, the rectifying circuit 57 that rectifies the alternating current induced by the power receiving coil 51, and the output of the rectifying circuit 57. A charging circuit 58 and a modulation circuit 54 that transmits an information signal of the portable device 50 to the power supply base 10 are provided.

  The portable device 50 transmits an information signal to the power supply base 10 by the modulation circuit 54 so that the power supply base 10 supplies optimal power. The modulation circuit 54 transmits the output voltage, output current, battery state, temperature, and the like of the power receiving coil 51 to the power supply base 10 as information signals. The modulation circuit 54 includes a series circuit 60 of an impedance element 61 and a switching element 62 and an input circuit 63 that controls the switching element 62 of the series circuit 60 to be turned on and off. The series circuit 60 is connected in parallel with the power receiving coil 51 and switches the switching element 62 on and off to change the load impedance of the power receiving coil 51. In the modulation circuit 54 of FIG. 4, the impedance element 61 is a capacitor 61A, and the switching element 62 is an FET 62A. However, as the impedance element, a coil or a resistor can be used in place of the capacitor, and an element in which a capacitor, a coil, and a resistor are connected in series or in parallel can be used. Moreover, a transistor can also be used for a switching element instead of FET.

  The input circuit 63 uses the output voltage, output current, battery voltage, fully charged state, battery temperature, etc. of the rectifier circuit 57 as information signals in a time series, turns the switching element 62 on and off with digital signals, using the information signals as digital signals. The load impedance of the power receiving coil 51 is changed by switching. That is, the modulation circuit 54 changes the load impedance of the power receiving coil 51 with the digital signal of the information signal, and transmits the information signal to the power supply base 10. The input circuit 63 repeatedly converts the output voltage, output current, battery voltage, full charge state, battery temperature, etc. into digital signals in order at a predetermined cycle, and switches the switching element 62 on and off with this digital signal. The signal information signal is transmitted to the power supply base 10. In order to identify the order of various information signals such as output voltage, output current, battery voltage, fully charged state, battery temperature, etc., the modulation circuit 54 that transmits a plurality of information signals outputs a plurality of information signals after the synchronization signal. To transmit. The modulation circuit 54 modulates the load impedance of the power receiving coil 51 with the synchronization signal and the information signal, and transmits the information signal to the power supply base 10.

  The power supply base 10 is transmitted from the case 20, the power transmission coil 11 that is disposed in the case 20 and electromagnetically coupled to the power receiving coil 51, the AC power supply 12 that supplies AC power to the power transmission coil 11, and the portable device 50. And a control circuit 15 for controlling the AC power supply 12 with the information signal detected by the demodulation circuit 14.

  As shown in FIG. 5, the case 20 is provided with a flat upper surface plate 21 on which the portable device 50 is placed on the upper surface. In the power supply stand 10 of FIG. 5, the entire top plate 21 is horizontally arranged in a flat shape. The top plate 21 has a size that allows various portable devices 50 having different sizes and outer shapes to be placed thereon. Further, the top plate 21 may have a structure in which a peripheral wall or the like is provided around the top plate 21, the mobile device is set inside the peripheral wall, and the mobile device is set at a fixed position.

  The power transmission coil 11 is wound in a spiral shape on a surface parallel to the upper surface plate 21 and radiates an alternating magnetic flux above the upper surface plate 21. The power transmission coil 11 radiates an alternating magnetic flux orthogonal to the upper surface plate 21 above the upper surface plate 21. The power transmission coil 11 is supplied with AC power from the AC power source 12 and radiates AC magnetic flux above the upper surface plate 21. The power transmission coil 11 is substantially equal to the outer diameter of the power reception coil 51 and efficiently conveys power to the power reception coil 51. The power supply base 10 that sets the portable device 50 at a free position on the top plate 21 includes a transfer mechanism (not shown) that causes the power transmission coil 11 to approach the power reception coil 51 of the portable device 50. In the power supply stand for setting the portable device at a fixed position on the upper surface plate, the power transmission coil is arranged at a position approaching the power receiving coil of the portable device to be set.

  The AC power supply 12 supplies AC power to the power transmission coil 11. The power supply stand 10 that moves the power transmission coil 11 so as to approach the power reception coil 51 connects AC power to the power transmission coil 11 via a flexible lead wire (not shown). Although not shown, the AC power supply 12 includes an oscillation circuit and a power amplifier that amplifies the AC output from the oscillation circuit. As the AC power, for example, AC power of several hundred kHz to several tens of MHz is supplied to the power transmission coil 11.

  The demodulation circuit 14 detects an information signal from the amplitude fluctuation of the AC waveform of the power transmission coil 11. When the switching element 62 of the modulation circuit 54 is switched on and off, the amplitude of the AC waveform flowing through the power transmission coil 11 changes. The demodulation circuit 14 shapes an AC waveform amplitude variation of the power transmission coil 11 with a waveform shaping circuit (not shown), detects a change in load impedance of the power reception coil 51, and detects an information signal. The demodulating circuit 14 also detects a synchronization signal transmitted from the portable device 50 and detects an information signal transmitted in order following the synchronization signal.

  An information signal detected by the demodulation circuit 14 is input to the control circuit 15. The control circuit 15 controls the AC power supply 12 with the information signal to control the power supplied from the AC power supply 12 to the power transmission coil 11 to an optimum value. The portable device 50 set on the power supply base 10 transmits an information signal to the power supply base 10 by the modulation circuit 54. The power supply base 10 detects the information signal and adjusts the AC power supplied to the power transmission coil 11. If the power base 10 cannot detect the information signal from the portable device 50, the power base 10 cannot supply normal power to the power transmission coil 11. In order to reliably detect the information signal from the portable device 50, the control circuit 15 of the power supply base 10 controls the power supplied to the power transmission coil 11.

  A line A in FIG. 6 indicates a boundary between a detection area in which an information signal can be transmitted from the portable device 50 to the power supply base 10 and a non-detection area (indicated by hatching in the drawing) where the information signal cannot be transmitted. In this figure, the horizontal axis represents the load current of the power receiving coil 51, and the vertical axis represents the feed power (supply voltage in the figure) of the power transmission coil 11. As shown in this figure, in the region where the load current of the power receiving coil 51 is large, if the supply voltage (feed power) of the power transmission coil 11 is small, the information signal cannot be transmitted. This is because when the supply voltage (feed power) of the power transmission coil 11 is low, the amplitude fluctuation of the AC waveform of the power transmission coil 11 becomes small as shown in FIG. When the supply voltage (feeding power) of the power transmission coil 11 is increased, as shown in FIG. 3, the amplitude fluctuation of the AC waveform increases, and an information signal can be transmitted.

  When the portable device 50 is set on the power supply stand 10, the set portable device 50 transmits an information signal to the power supply stand 10. At this time, if the load current of the portable device 50 is large and the power supplied to the power transmission coil 11 is small, the information signal cannot be detected. The power supply stand 10 that cannot detect the information signal cannot set the power supplied to the power transmission coil 11 to an optimum value.

  In order to prevent the above adverse effects, the control circuit 15 of the power supply base 10 reliably detects the information signal as follows. The power supply base 10 includes a detection circuit (not shown) that detects that the portable device 50 is set. For example, the detection circuit is provided with a detection coil on the upper surface plate 21, inputs a pulse signal to the detection coil, excites the receiving coil 51 with this pulse signal, and is output from the receiving coil 51 excited with the pulse signal. It is possible to detect that the portable device 50 is set by detecting the echo signal. Further, it is possible to detect that the portable device 50 has been set by providing a limit switch or the like on the top plate 21 and switching the portable device 50 to be set.

  As shown by the line B in FIG. 6, the power supply base 10 controls the supply voltage of the power transmission coil 11 and adjusts the supply voltage of the power transmission coil 11 to the optimum value while reliably detecting the information signal. When the power supply base 10 detects that the portable device 50 is set with a detection circuit, the control circuit 15 can transmit the power supplied to the power transmission coil 11 from the portable device 50 to the power supply base 10 at the maximum. The information signal is detected by setting the initial power. In FIG. 6, the maximum initial power is set to a power at which a supply voltage for supplying AC power to the power transmission coil 11 is 11V. In FIG. 6, the maximum load current of the portable device 50 is 2A, and the supply voltage of the power transmission coil 11 that cannot detect the information signal in this state is about 10V. Therefore, when the supply voltage of the power transmission coil 11 is set to 11 V and the maximum initial power is set, the power supply base 10 can detect the information signal even if the load current of the portable device 50 is the maximum current. Thereafter, the power supply base 10 gradually reduces the power supplied to the power transmission coil 11 while detecting an information signal from the mobile device 50, and sets it to 6 V, which is optimal for the mobile device 50. The power supply base 10 determines an optimum power supply power to be supplied to the power transmission coil 11 by an information signal transmitted from the portable device 50. That is, the power required by the portable device 50 is requested to the power supply base 10 by an information signal, and the power supply base 10 sets the power supplied to the power transmission coil 11 by this information signal. Moreover, the power supply stand 10 calculates the power transmission efficiency by the information signal from the portable device 50 and the power supplied to the power transmission coil 11, and the power transmission efficiency to be calculated is an optimal value or a pre-set preferred region. The power supplied to the power transmission coil 11 can also be controlled.

  Furthermore, when the load of the portable device 50 fluctuates and the load current temporarily increases in a state where power is transferred while being set on the power supply base 10, the power supply base 10 may not be able to detect the information signal. For example, when the mobile device 50 is a mobile phone and the battery is charged, the load fluctuation of the mobile device 50 occurs when the phone is received and a reception sound is produced or the vibrator vibrates. For example, in FIG. 6, if the load current of the portable device 50 exceeds 1 A in the state where the supply voltage of the power transmission coil 11 is 6 V and the power is conveyed, the power supply base 10 cannot detect the information signal. In this non-detection state, the control circuit 15 controls the AC power supply 12 to increase the supply power so that the supply voltage of the power transmission coil 11 becomes higher than 6V. When the supply voltage of the power transmission coil 11 is increased and the power feeding power is increased, an information signal can be detected, so that the power supply base 10 can detect the information signal of the portable device 50.

  That is, when the power supply base 10 enters a non-detection state in which the information signal on the portable device 50 side cannot be detected, the power supply power of the power transmission coil 11 is increased to a level at which the information signal can be detected, and the information signal from the portable device 50 is detected. To do. The AC power supply 12 is controlled by the information signal to be detected, and the power supplied to the power transmission coil 11 is adjusted to an optimum state. For example, when the load current of the portable device 50 decreases to 1 A or less, the power supplied to the power transmission coil 11 is reduced to an optimum power, and power is transferred from the power supply base 10 to the portable device 50.

The above power supply stand 10 carries power to the portable device 50 by the following operation.
(1) When the portable device 50 is placed on the upper surface plate 21 of the case 20, the power supply base 10 detects that the portable device 50 is set. In this state, the power transmission coil 11 approaches the power reception coil 51.
(2) The power supply base 10 detects the information signal from the portable device 50 by setting the feeding power of the power transmission coil 11 to the maximum initial power.
(3) The power supply base 10 controls the AC power supply 12 with the information signal transmitted from the portable device 50 to gradually reduce the power supplied to the power transmission coil 11 and adjust the power supplied to the power transmission coil 11 to the optimum power. Then, power is transferred from the power transmission coil 11 to the power reception coil 51.
(4) When power is being transferred from the power supply base 10 to the mobile device 50, the load current of the mobile device 50 increases and the power supply base 10 enters a non-detection state in which an information signal cannot be detected. The power supply 12 is controlled to increase the power supplied to the power transmission coil 11 to a power at which an information signal can be detected.
(5) The power supply base 10 detects the information signal transmitted from the portable device 50, and while maintaining the state in which the information signal can be transmitted, the power supply power of the power transmission coil 11 is gradually reduced and set to the optimum power. To do. In this state, power is transferred from the power transmission coil 11 to the power reception coil 51.
(6) When the portable device 50 is the battery built-in device 50A and the built-in battery 52 is fully charged, the power supply base 10 detects the full charge signal transmitted from the portable device 50, and the control circuit 15 The power supply to the power transmission coil 11 is stopped.
In a state where the portable device 50 does not stop power transfer due to a light or the like, power is continuously transferred from the power transmission coil 11 to the power receiving coil 51, and power is supplied from the power supply stand 10 to the portable device 50.

  In the power transfer method of the present invention, power is transferred from the power supply stand to the portable device in a contactless manner, and further, the power signal is transferred from the power supply stand to the portable device while stably transmitting information signals from the portable device to the power supply stand. It is suitably used for stable contactless charging of a battery built-in device such as a device.

DESCRIPTION OF SYMBOLS 10 ... Power supply stand 10A ... Charging stand 11 ... Power transmission coil 12 ... AC power supply 14 ... Demodulation circuit 15 ... Control circuit 20 ... Case 21 ... Top plate 50 ... Portable device 50A ... Battery built-in device 51 ... Power receiving coil 52 ... Battery 54 ... Modulation Circuit 57 ... Rectifier circuit 58 ... Charging circuit 60 ... Series circuit 61 ... Impedance element 61A ... Capacitor 62 ... Switching element 62A ... FET
63 ... Input circuit 110 ... Power source 111 ... Power transmission coil 150 ... Portable device 151 ... Power reception coil 184 ... Modulation circuit 186 ... Switching element 187 ... Condenser

Claims (6)

The portable device (50) is set on the power supply stand (10), and the power transmission coil (11) of the power supply stand (10) and the power receiving coil (51) of the portable device (50) are electromagnetically coupled to each other. ) Power transfer from the power transmission coil (11) to the power reception coil (51) of the portable device (50),
In a state where power is transferred from the power transmission coil (11) of the portable device (50) to the power reception coil (51), the power supply base (10) is modulated by a modulation method in which the portable device (50) changes the load impedance of the power reception coil (51). Transmit information signals to
The power supply base (10) detects a change in load impedance of a power receiving coil (51) that is electromagnetically coupled to the power transmitting coil (11), and detects the information signal.
The power supply (10) carries power from the power transmission coil (11) to the power reception coil (51) while controlling the power feeding power of the power transmission coil (11) with the information signal transmitted from the portable device (50) side. A transport method,
The power supply base (10) sets the power supplied to the power transmission coil (11) to the maximum initial power that can transmit the information signal from the portable device (50) to the power supply base (10), and then transmits the information signal. The electric power conveyance method which reduces the electric power feeding of a power transmission coil (11), and makes it the optimal supply electric power. The portable device (50) is set on the power supply stand (10), and the power transmission coil (11) of the power supply stand (10) and the power receiving coil (51) of the portable device (50) are electromagnetically coupled to each other. ) Power transfer from the power transmission coil (11) to the power reception coil (51) of the portable device (50),
In a state where power is transferred from the power transmission coil (11) of the portable device (50) to the power reception coil (51), the power supply base (10) is modulated by a modulation method in which the portable device (50) changes the load impedance of the power reception coil (51). Transmit information signals to
The power supply base (10) detects a change in load impedance of a power receiving coil (51) that is electromagnetically coupled to the power transmitting coil (11), and detects the information signal.
The power supply (10) carries power from the power transmission coil (11) to the power reception coil (51) while controlling the power feeding power of the power transmission coil (11) with the information signal transmitted from the portable device (50) side. A transport method,
When the power supply stand (10) enters a non-detection state in which the information signal on the portable device (50) side cannot be detected, the power supplied to the power transmission coil (11) is increased to a level at which the information signal can be detected, and the portable device ( 50) A power transfer method configured to transmit an information signal from the power supply base (10) to the power supply base (10).   The power supply base (10) stores the maximum feeding power of the power transmission coil (11) that can detect the information signal at the maximum load of the portable device (50), and the power supply base (10) cannot detect the information signal. The power supply stand (10) sets the power supply power of the power transmission coil (11) to the maximum power supply power and detects the information signal from the portable device (50) to the power supply stand (10) in the state. Power transfer method.   The said power supply stand (10) detects the change of the load impedance of a receiving coil (51) from the change of the voltage amplitude of a power transmission coil (11), and detects an information signal in any one of Claim 1 thru | or 3. Power transfer method.   The portable device (50) is connected in parallel with the power receiving coil (51) to connect a series circuit (60) of a capacitor (61A) and a switching element (62), and the switching element (62) is turned on and off to receive the power receiving coil. 5. The power carrying method according to claim 1, wherein the information signal is transmitted by changing the load impedance of (51).   The power carrying method according to any one of claims 1 to 5, wherein the portable device (50) transmits the power induced in the power receiving coil (51) to the power supply stand (10) as an information signal.

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