JP2012100406A - Radio charger and radio charging method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio charger with a metal housing or a part of the housing made of metal and to provide a radio charging method using the same.SOLUTION: A radio charger comprises: resonance capacitors each connected in series; a resonance circuit for resonating with frequency of external power transmitted by radio from outside, the circuit being composed of a resonance coil having a closed loop magnetic core, a part of whose sectional area where the magnetic core has no coil is smaller than a sectional area of coil part; and a secondary battery to be charged with the external power through the resonance circuit. A housing of the charger or a part of the housing is made of metal. As for the resonance capacitors, a reference resonance capacitor and one or more amendment resonance capacitors are prepared. The amendment resonance capacitors can be connected to the reference resonance capacitor and are used so that the resonance circuit resonates with the frequency of the external power.

Description

The present invention wirelessly charges an external electric power to a secondary battery via a resonance circuit including a resonance coil and a resonance capacitor connected in series to the resonance coil. The present invention relates to a wireless charging device made of metal and a wireless charging method thereof.

In recent years, electronic devices that charge a secondary battery wirelessly through a resonance circuit including a resonance coil and a resonance capacitor connected in series to the resonance coil in a wireless manner are being actively developed or put into practical use (non-patent) Reference 1). Examples of the electronic device include a brushless DC motor having a secondary power source of the present applicant's invention (Patent Document 1) and a rechargeable cardiac pacemaker (Non-Patent Document 2). In addition, in connection with the environmental problem of global warming, a wireless charging device that wirelessly charges a secondary battery mounted on an electric vehicle from the outside has been actively researched and developed. Examples of the wireless charging device include Non-Patent Document 3.

FIG. 7 shows a conventional wireless charging apparatus. FIG. 7 also shows an external power oscillation device 72 that is wirelessly connected to a conventional wireless charging device 71 through a wall 72d of a metal housing. The external power oscillation device 72 includes an AC power source 72a and the AC power source 72a. A primary coil 72c connected to the power source 72a and a primary capacitor 72b connected in series to the primary coil 72c. The conventional wireless charging device 71 can supply external power wirelessly from the external power oscillation device 72 via the primary coil 72c, and is connected in series to the secondary coil 73a having a self-inductance L and the secondary coil 73a. A resonant circuit 73 composed of a secondary capacitor 73 b having a capacitance C to be connected, a full-wave rectifier circuit 74 composed of four diodes 74 a, 74 b, 74 c and 74 d connected to the resonant circuit 73, and the full-wave rectifier circuit 74 Connected to the charging capacitor 75 having a capacity Cc, a charging controller 76 connected to the charging capacitor 75 for controlling charging, and a lithium ion secondary battery 77 connected to the charging controller 76 for charging external power. Connected to the lithium ion secondary battery 77, regulates the output voltage 77 a, 77 b of the lithium ion secondary battery 77, and the outside of the wireless charging device 71 Voltage charging capacity characteristic data 79c having the temperature as a parameter of the lithium ion secondary battery 77 is input to a memory (not shown) from the regulator 78 that outputs the output voltages 78a and 78b and the wireless charging device 71. Connected to the lithium ion secondary battery 77, monitoring the output voltages 77 a and 77 b of the lithium ion secondary battery 77, and in contact with the lithium ion secondary battery 77, disposed temperature sensor A voltage charge capacity characteristic having the temperature as a parameter of the lithium ion secondary battery 77 stored in the memory and the output voltages 77a and 77b and the output voltage 77c. The lithium ion secondary battery 77 is overcharged, and has a function of calculating the charge capacity of the lithium ion secondary battery 77. If it is determined that the lithium ion secondary battery 77 is overdischarged, a level H overcharge detection signal 79a is output to the charge controller 76. And an overcharge detection signal 79a (level H when overcharge is detected) and an overdischarge detection signal 79b (when overdischarge is detected, to the outside of the wireless charging device 71. Overcharge / overdischarge detection signal output means 79 for outputting level H).

FIG. 8 is a plan layout diagram of a primary coil of an external power oscillation device used in the related art and a secondary coil of a conventional wireless charging device. The primary coil 81 has a winding 81b wound around a U-shaped magnetic core 81a, and is connected to an external power source via a primary capacitor constituting a resonance circuit (not shown). Similarly, the secondary coil 82 has a winding 82b wound around a U-shaped magnetic core 82a, and forms a resonance circuit with the secondary capacitor (not shown). At the time of wireless charging, the primary coil 81 and the secondary coil 82 are disposed in close proximity to each other via a wall 83 of a metal casing. The main magnetic flux generated by the primary coil 81 passes through the wall 83, passes around the magnetic core 82 a, passes through the wall 83 again and returns to the magnetic core 81 a, and passes through the wall 83. There is a returning magnetic flux 84b. On the other hand, the main magnetic flux due to the resonance current generated by the electromotive force induced in the secondary coil 82 passes through the wall 83 and passes around the magnetic core 81a, and again passes through the wall 83 and returns to the magnetic core 82a. There is a magnetic flux 85a and a magnetic flux 85b returning through the wall 83.

FIG. 9 is a cross-sectional layout view of another primary coil of the external power oscillation device used in the related art and another secondary coil of the conventional wireless charging device. The primary coil 91 has a winding 91b wound around a magnetic core 91a having an E-shaped cross section, and is connected to an external power source via a primary capacitor constituting a resonance circuit (not shown). Similarly, the secondary coil 92 includes a winding 92b wound around a magnetic core 92a having an E-shaped cross section, and constitutes a secondary capacitor and a resonance circuit (not shown). At the time of wireless charging, the primary coil 91 and the secondary coil 92 are disposed in close proximity to each other via a wall 93 of a metal casing. The main magnetic flux generated by the primary coil 91 passes through the wall 93, passes around the magnetic core 92 a, passes through the wall 93 again and returns to the magnetic core 91 a, and passes through the wall 93. There is a returning magnetic flux 94b. On the other hand, the main magnetic flux due to the resonance current generated by the electromotive force induced in the secondary coil 92 is a magnetic flux that passes through the wall 93 and passes around the magnetic core 91a, and again passes through the wall 93 and returns to the magnetic core 92a. 95a and magnetic flux 95b returning through the wall 93.

However, in FIG. 8, since the magnetic fluxes 84b and 85b passing through the wall 83 generate eddy current in the wall 83 and eddy current loss occurs, there is a problem that the wireless charging efficiency is lowered. In FIG. 9, the magnetic flux 94b and the magnetic flux 95b passing through the wall 93 generate an eddy current in the wall 93, resulting in an eddy current loss. In order to solve the problem of eddy current loss caused by the magnetic flux 85b shown in FIG. 8 and the magnetic flux 95b shown in FIG. 9, the present invention discloses a partial cross-sectional area of a magnetic core having no winding disclosed in Patent Document 2. A secondary coil (hereinafter referred to as a resonance coil) having a closed-loop magnetic core smaller than the cross-sectional area of the winding portion was employed.

The first resonance coil used in the present invention is shown in FIG. 5 as a plan layout of the first primary coil of the external power oscillation device used in the present invention and the first resonance coil of the wireless charging apparatus of the present invention. I will explain it. The first primary coil 51 and the first resonance coil 52 are disposed so as to approach and face each other with the wall 53 of the housing interposed therebetween, and the first primary coil 51 includes a U-shaped magnetic core 51a and the magnetic core. The first resonance coil 52 is similarly composed of a rectangular magnetic core 52a and a winding 52b wound around the magnetic core 52a, and is smaller than the cross-sectional area of the winding portion 52c. The main magnetic flux generated by energizing the first primary coil 51 has a narrow magnetic core portion 52d having a cross-sectional area, passes through the wall 53, travels around the magnetic core 52a, and again passes through the wall 53. There is a magnetic flux 54a that passes through and returns to the magnetic core 51a, a magnetic flux 54b that passes through the wall 53 and returns to the magnetic core 51a, and a magnetic flux 54c that passes through the narrow magnetic core portion 52d of the resonance coil 52 and returns to the magnetic core 51a. On the other hand, the electromotive voltage induced in the resonance coil 52 The main magnetic flux generated by the swaying resonance current passes through the wall 53, passes around the magnetic core 51a, passes through the wall 53 again and returns to the magnetic core 52a, and the narrow magnetic core portion 52d. There is a magnetic flux 55b that returns to the magnetic core 52a and a magnetic flux 55c that passes through the wall 53 and returns to the magnetic core 52a. The width 56b of the narrow magnetic core portion 52d with respect to the width 56a of the winding portion 52c of the magnetic core 52a is determined by the amount of the magnetic flux 55b passing through the narrow magnetic core portion 52d and the magnetic flux generated by the first primary coil 51. Of the magnetic flux 54c that does not pass through the magnetic core 52a and short-circuits through the narrow magnetic core portion 52d, and the amount of the magnetic flux 54b that passes through the wall 53 and the amount of the magnetic flux 55c that cause eddy current loss. Is taken into consideration so that the total wireless charging efficiency is maximized.

Similarly, the second resonance coil used in the present invention includes the second primary coil of the external power oscillation device used in the present invention and the second resonance coil of the wireless charging device of the present invention shown in FIG. This will be described with reference to a cross-sectional arrangement drawing. The second primary coil 61 and the second resonance coil 62 are arranged close to and opposite to each other with the wall 63 of the housing interposed therebetween, and the second primary coil 61 includes a magnetic core 61a having an E-shaped cross section. Similarly, the second resonance coil 62 is composed of a magnetic core 62a having a sun-shaped cross section and a winding 62b wound around the winding portion 62c. The magnetic core 62a has a narrow magnetic core portion 62d having a smaller cross-sectional area than the cross-sectional area of the wire portion 62c, and main magnetic flux generated by energizing the second primary coil 61 passes through the wall 63. , And again passes through the wall 63 and returns to the magnetic core 61 a, passes through the wall 63 and returns to the magnetic core 61 a, and passes through the narrow magnetic core portion 62 d of the resonance coil 62. There is a magnetic flux 64c returning to the magnetic core 61a, while being induced in the resonance coil 62. The main magnetic flux generated by the resonance current generated by the electromotive force generated is a magnetic flux 65a that passes through the wall 63, passes around the magnetic core 61a, returns to the magnetic core 62a again, and a narrow magnetic core portion 62d. There is a magnetic flux 65b that passes through the wall 63 and returns to the magnetic core 62a, and a magnetic flux 65c that passes through the wall 63 and returns to the magnetic core 62a. The width 66b of the narrow magnetic core portion 62d relative to the width 66a of the winding portion 62c of the magnetic core 62a is such that the amount of the magnetic flux 65b passing through the narrow magnetic core portion 62d and the magnetic flux generated by the primary coil 61 are the magnetic core 62a. In consideration of the amount of the magnetic flux 64c that does not pass through the narrow magnetic core portion 62d and is short-circuited, and the amount of the magnetic flux 64b that passes through the wall 63 and the amount of the magnetic flux 65c that cause eddy current loss. The total wireless charging efficiency is determined to be maximized.

JP 2007-217173 A JP 2006-8542 A Wireless power supply 2010 Nikkei Electronics edit Taku Sato et al. Magn. Soc. Jpn. Vol. 32 27 (2008) Hiroko Kaneko et al. IEEE Trans. IA, Vol. 130 734 (208)

However, the wireless charging device of the present invention is significantly different from Patent Document 2 in the following points. That is, in Patent Document 2, the resonance coil captures a long wave of weak power, whereas the resonance coil of the wireless charging device of the present invention must capture much higher power wirelessly. As a result, when there is only one secondary capacitor (hereinafter referred to as “resonance capacitor”), the resonance current during resonance greatly changes as the magnitude of the electromotive voltage induced in the resonance coil by the wireless power from the outside changes. At the same time, the magnetic flux generated in the magnetic core by the resonance current causes the narrow magnetic core portion 52d shown in FIG. 5 or the narrow magnetic core portion 62d shown in FIG. 6 to be magnetically saturated, so that the inductance of the resonant coil also changes. Therefore, the resonance frequency of the resonance circuit determined by Equation 1 shown below deviates from the frequency of the external power, so that the reactance of the resonance coil, ωL and the reactance of the resonance capacitor, −1 / ωC do not cancel each other, and this corresponds to that. As a result, the resonance current is reduced and sufficient charging efficiency cannot be obtained.

Where f is the resonant frequency of the resonant circuit,
L is the inductance of the resonant coil,
C is the capacity of the resonant capacitor.

The resonance current flowing through the resonance coil is expressed by the equation (2).
Where I is the resonance current,
V is an electromotive voltage induced between both ends of the resonance coil,
R is the resistance of the resonant coil.
At the time of resonance, the resonance current I is proportional to the electromotive voltage V, and the phases thereof are the same.

The Q value of the resonance coil is expressed by the equation (3).
Where Q is the Q value,
ω is the angular frequency of the external power,
L is the self-inductance of the resonant coil,
R is the resistance of the resonant coil.

The voltage between both ends of the resonance coil at the time of resonance is expressed by the equation (4).
Where v is the voltage across the resonant coil,
j is an imaginary number,
Q is the Q value,
V is an electromotive voltage induced between both ends of the resonance coil.
At the time of resonance, the voltage v between both ends of the resonance coil is delayed by 90 degrees compared to the electromotive voltage V induced between both ends of the resonance coil, that is, the phase is delayed by 90 degrees compared to the resonance current I. become.

External power that consists of a resonant capacitor connected in series with each other and a resonant coil that has a closed-loop magnetic core whose partial cross-sectional area of the magnetic core without winding is smaller than the cross-sectional area of the winding part. In the wireless charging device, which includes a resonance circuit that resonates at a frequency of and a secondary battery that charges external power via the resonance circuit, and the casing is made of metal or part of the casing is made of metal, the resonance capacitor includes And a reference resonance capacitor and one or more correction resonance capacitors that can be connected to the reference resonance capacitor and are used to resonate the resonance circuit to the frequency of the external power.

The correction resonance capacitor is connected in series or in parallel to the reference resonance capacitor by an analog switch, or is disconnected from the reference resonance capacitor.

The wireless charging device includes a digital reference signal generating unit that generates a digital reference signal having a frequency sufficiently higher than the frequency of the external power.

The wireless charging device generates a digital signal by digitizing means for digitizing the voltage between both ends of the resonance coil into a digital voltage having the same frequency as the frequency of the external power, and by advancing its phase by 90 degrees. It has digital signal generating means comprising means for advancing the phase by 90 degrees.

Corresponding to the increase in the resonance current, the correction resonance capacitor is connected in parallel to the reference resonance capacitor, or the correction resonance capacitor is disconnected from the series connection from the reference resonance capacitor, and the resonance By switching the capacitor so that its capacity increases, and corresponding to the decrease in the resonance current, the correction resonance capacitor is disconnected from the parallel connection from the reference resonance capacitor, or the reference The resonant capacitor for correction is connected in series to a resonant capacitor, and the resonant capacitor is switched so as to reduce its capacitance, thereby resonating the resonant circuit at the frequency of the external power.

The 90-degree advancement of the digital voltage by the phase advancement means is performed based on the count number of the digital reference signal output from the digital reference signal generation means, and the switching timing of the resonance capacitor is: This is performed based on the count number of the digital reference signal from the rising or falling edge of the digital signal.

By using the wireless charging device and the wireless charging method of the present invention, the resonance circuit of the wireless charging device in which the casing is made of metal or part of the casing made of metal can resonate with the frequency of the external power, Efficient wireless charging is possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a block diagram of a first wireless charging apparatus of the present invention. Also shown is an external power oscillation device 2 that is wirelessly connected to the wireless charging device 1 via a metal housing wall 2d. The external power oscillation device 2 includes an AC power source 2a, a primary capacitor 2b connected to the AC power source 2a, and a primary coil 2c. The wireless charging device 1 is close to and faces the primary coil 2c of the external power oscillation device 2. A resonant coil 3a having an inductance L0, a reference resonant capacitor 3b having a capacitance C0 connected in series to the resonant coil 3a, and a capacitor C1 connected in parallel to the resonant capacitor 3b via analog switches AS1 and 3d. A resonance circuit 3 comprising a correction resonance capacitor 3c, a correction resonance capacitor 3e with a capacitance C2 connected in parallel to the resonance capacitor 3b via analog switches AS2 and 3f, and a bridge connected to the resonance circuit 3 Full-wave rectifier circuit 4 composed of connected diodes 4a, 4b, 4c and 4d, and charging of capacitor Cc connected to full-wave rectifier circuit 4 A capacitor 5; a charging controller 6 connected to the charging capacitor 5 to control charging; a lithium ion secondary battery 7 connected to the charging controller 6 to charge external power; and the lithium ion secondary battery 7 and a regulator 8 for regulating the output voltages 8a and 8b output from the wireless charging device 1 to the outside, and a digitizing means for digitizing the voltage between both ends of the resonance coil 3a into a digital voltage. 9a and the digital voltage output from the digitizing means are advanced by 90 degrees to output a digital signal, and the digital signal generating means 9 comprising the phase advanced 90 means 9b is sufficiently larger than the frequency of the external power. Digital reference signal generating means 17 for generating a digital reference signal of frequency and the analog switches AS1, 3d and AS2, 3f are turned on / off. The correction resonance capacitor connection switching means 18 for connecting or disconnecting the correction resonance capacitors 3c, 3e to the reference resonance capacitor 3b and the temperature of the lithium ion secondary battery 7 from the outside of the wireless charging device 1 in advance. Is input to an internal memory (not shown), connected to the lithium ion secondary battery 7, and the output voltages 7a and 7b of the lithium ion secondary battery 7 are monitored. The output voltage 7c of the temperature sensor (not shown) placed in contact with the lithium ion secondary battery 7 is input, the output voltages 7a and 7b, the output voltage 7c, and the memory stored in the memory, The function of collating with the voltage charge capacity characteristic of the lithium ion secondary battery 7 having temperature as a parameter, and calculating the charge capacity of the lithium ion secondary battery 7 And when the lithium ion secondary battery 7 is determined to be overcharged, it outputs a level H overcharge detection signal 9a to the charge controller 6, and the lithium ion secondary battery 7 If it is determined that the battery is overdischarged, an overdischarge detection signal 9b of level H is output to the regulator 8, and an overcharge detection signal 9a (when overcharge is detected, Level overcharge detection signal output means 9 for outputting level H) and overdischarge detection signal 9b (level H when overdischarge is detected).

First, the time change of each signal at the time of wireless charging shown in FIG. 3 will be described. 3A shows a time change (oscillation start, oscillation in progress, ON, oscillation stop, OFF) of the switch (not shown) 31 of the external power oscillation device 2, and FIG. The time change of the output signals 6a, 32 (charging start, charging, H, charge stop, end, L), FIG. 3C shows the time change of the voltage difference 33 between the output voltage 8a of the regulator 8 and the output voltage 8b, FIG. 3D shows the time change of the electromotive voltage 34 induced across the resonance coil 3a, FIG. 3E shows the time change of the voltage 35 across the resonance coil 3a, and FIG. FIG. 3G shows a time change of the digital voltage 36 output from the digitizing means 9a of the digital signal generating means 9, and the digital reference signal output from the means 9b of the digital signal generating means 9 by advancing the phase by 90 degrees. Cow of digital reference signal 17a output from generating means 17 FIG. 3 (h) shows the reference resonance of the correcting resonance capacitor 3c of the correcting resonance capacitor connection switching means 18 based on the number of the signals. Resonance capacitor connection switching signal 38 for correction to analog switches AS1 and 3d for connection to capacitor 3b or disconnection from reference resonance capacitor 3b (the phase of electromotive voltage 34 is 30 to 150 degrees, respectively) FIG. 3 (i) shows that the correction resonance capacitor connection switching means 18 of the correction resonance capacitor connection switching means 18 is connected to the reference resonance capacitor 3b. , The resonant capacitor for correction to the analog switches AS2 and 3f for disconnecting from the reference resonant capacitor 3b Connection switching signal 39 (39a, 39 b respectively, the phase of the electromotive force 34 is H from 60 degrees to 300 degrees from H, 240 degrees to 120 degrees) showing the time variation of.

The wireless charging operation of the first wireless charging device 1 of the present invention shown in FIG. 1 will be described using the wireless charging flowchart shown in FIG. 2 and the time variation of each signal during wireless charging shown in FIG. To do. First, the primary coil 2c of the external power oscillation device 2 and the resonance coil 3a of the resonance circuit 3 of the first wireless charging device 1 are arranged close to each other and face each other. Thereafter, the external power oscillation device 2 starts oscillation (S1). The charge controller 6 outputs a charge start signal 6a of level H to the correcting resonance capacitor connection switching means 18 and the digital reference signal generating means 17 (S2). When the outputs 8a and 8b of the regulator 8 exceed the reference voltage (S3), the correction resonance capacitor connection switching means 18 starts switching the connection of the correction resonance capacitors 3c and 3e to the reference resonance capacitor 3b (S4). . When the correction resonance capacitor connection switching means 18 detects the rising edge of the digital signal 37 (S5), first, after t10, the correction signal is corrected based on the count number of the digital reference signal 17a output from the digital reference signal generation means 17. The output 38a of the resonance capacitor connection switching means 18 becomes level H, turns on AS1, 3d (S6), and after t20, the output 39a of the correction resonance capacitor connection switching means 18 becomes level H, AS2, 3f Is turned on (S7), and after t11, the output 38a of the correcting resonance capacitor connection switching means 18 becomes level L, and AS1, 3d is turned off (S8), and after t21, the correcting resonance capacitor connection switching means 18 The output 39a becomes level L, and AS2 and 3f are turned off (S9). Since the charge controller 6 has not yet issued the level L charge end signal 6a, the process returns to S5, and when the correcting resonance capacitor connection switching means 18 detects the falling edge of the digital signal 37 (S5), the digital reference Based on the count number of the digital reference signal 17a output from the signal generating means 17, first, after t10, the output 38b of the correcting resonance capacitor connection switching means 18 becomes the level H and turns on AS1, 3d (S6). After t20, the output 39b of the correcting resonance capacitor connection switching means 18 becomes level H and turns on AS2 and 3f (S7). After t11, the output 38b of the correcting resonance capacitor connection switching means 18 becomes level L. Then, AS1 and 3d are turned off (S8), and after t21, the output 3 of the correcting resonance capacitor connection switching means 18 is output. b is a level L, turning off the AS2,3f (S9). This sequence is repeated, and then, in S10, when the external power oscillation device 2 finishes oscillating and the charge controller 6 outputs a charge end signal 6a of level L, the correcting resonant capacitor connection switching means 18 makes the reference Switching of the connection of the correcting resonance capacitors 3c and 3e to the resonance capacitor 3b is stopped (S11), and the wireless charging is finished.

In the flowchart at the time of wireless charging shown in FIG. 2, the overcharge / overdischarge detection signal output means 19 does not operate. When the overcharge / overdischarge detection signal output means 19 outputs an overcharge detection signal 19a of level H to the charge controller 6, the charge controller 6 will wait until the overcharge detection signal 19a becomes level L. Stop the charge control function. When the overcharge / overdischarge detection signal output means 19 outputs the overdischarge detection signal 19b of level H to the regulator 8, the regulator 8 keeps the regulator 8 until the overdischarge detection signal 19b becomes level L. Output to the outside of the wireless charging device 1 (output voltages 8a and 8b) is stopped.

FIG. 4 shows a block diagram of the second wireless charging apparatus of the present invention. An external power oscillation device 42 that is wirelessly connected to the wireless charging device 41 via a metal housing wall 42d is shown. The external power oscillation device 42 includes an AC power source 42a, a primary capacitor 42b connected to the AC power source 42a, and a primary coil 42c. The wireless charging device 41 is close to and faces the primary coil 42c of the external power oscillation device 42. A resonant coil 43a having an inductance L40 arranged in series and a reference resonant capacitor 43b having a capacitance C40 connected in series to the resonant coil 43a, and connected in series to the reference resonant capacitor 43b via analog switches AS1 and 43d, or The correction resonance capacitor 43c of the capacitor C41 separated from the reference resonance capacitor 43b and the capacitance C42 connected in series to the reference resonance capacitor 43b via the analog switches AS2 and 43f or separated from the reference resonance capacitor 43b And the correcting resonance capacitor 43e. An oscillation circuit 43; a full-wave rectification circuit 44 comprising diodes 44a, 44b, 44c, 44d connected to the resonance circuit 43; and a charging capacitor 45 connected to the full-wave rectification circuit 44; Connected to the charging capacitor 45 and connected to the charging controller 46 for controlling charging; the lithium ion secondary battery 47 connected to the charging controller 46 for charging external power; and the lithium ion secondary battery 47; A regulator 48 for regulating the output voltages 48a and 48b output to the outside by the wireless charging device 41, and a digitizing means 49a for digitizing the voltage between both ends of the resonance coil 43a into a digital voltage and the digitizing The phase of the digital voltage output from the means is advanced by 90 degrees and the digital signal is output. The reference resonance capacitor by turning on and off the analog signal AS1, 43d and AS2, 43f, the digital signal generating means 49, the digital reference signal generating means 417 for generating a digital reference signal having a frequency sufficiently larger than the frequency of the external power, The correction resonance capacitor connection switching means 418 for switching the connection of the correction resonance capacitors 43c and 43e to 43b and the voltage charging capacity characteristic of the lithium ion secondary battery 47 from the outside of the wireless charging device 41 in advance Input into a memory (not shown), connect to the lithium ion secondary battery 47, monitor the output voltages 47a and 47b of the lithium ion secondary battery 47, and contact the lithium ion secondary battery 47. The output voltage 47c of the arranged temperature sensor (not shown) is input, and the output voltage 4 7a and 47b, the output voltage 47c, and the voltage charge capacity characteristics of the lithium ion secondary battery 47 stored in the memory having the temperature as a parameter, and charging the lithium ion secondary battery 47 When it is determined that the lithium ion secondary battery 47 is overcharged, a level H overcharge detection signal 419a is output to the charge controller 46. When it is determined that the ion secondary battery 47 is overdischarged, the level 48 overdischarge detection signal 419b is output to the regulator 48, and at the same time, the overcharge detection signal 419a ( And an overcharge detection signal output means 419 that outputs an overdischarge detection signal 419b (level H when an overdischarge is detected). That.

First, the time change of each signal at the time of wireless charging shown in FIG. 3 will be described. 3A shows a time change (oscillation start, oscillation in progress, ON, oscillation stop, OFF) of the switch (not shown) 31 of the external power oscillation device 42, and FIG. The time change of the output signals 46a, 32 (charging start, charging, H, charge stop, end, L), FIG. 3C shows the time change of the voltage difference 33 between the output voltage 48a of the regulator 48 and the output voltage 48b, FIG. 3D shows the time change of the electromotive voltage 34 induced across the resonance coil 43a, FIG. 3E shows the time change of the voltage 35 across the resonance coil 43a, and FIG. FIG. 3 (g) shows the time change of the digital voltage 36 output from the digitizing means 49a of the digital signal generating means 49. FIG. 3G shows the digital reference signal output from the means 49b of the digital signal generating means 49 which is advanced by 90 degrees. The output from the generating means 417 The time variation of the digital signal 37 obtained by advancing the phase of the digital voltage 36 by 90 degrees based on the count number of the total reference signal 417a, FIG. 3 (h) shows the correction resonance capacitor of the correction resonance capacitor switching means 418. The resonance capacitor connection switching signal 38 for correction to the analog switches AS1 and 43d for connecting 43c to the reference resonance capacitor 43b (the phase of the electromotive voltage 34 is from 30 degrees to 150 degrees from H, 210 degrees from 38 degrees, respectively) Similarly, FIG. 3 (i) shows the correction resonance capacitor connection switching means 418 to analog switches AS2 and 43f for connecting the correction resonance capacitor 43e to the reference resonance capacitor 43b. Resonance capacitor connection switching signal 39 (39a, 39b, respectively) Phase voltage 34 indicates the time variation of H) from 60 degrees to 300 degrees from H, 240 degrees to 120 degrees.

The operation at the time of wireless charging of the second wireless charging device 41 of the present invention shown in FIG. 4 will be described using the flowchart at the time of wireless charging shown in FIG. 2 and the time change of each signal at the time of wireless charging shown in FIG. To do. A primary coil 42c of the external power oscillation device 42 and a resonance coil 43a included in the resonance circuit 43 of the first wireless charging device 41 are disposed close to and opposed to each other. Thereafter, the external power oscillator 42 starts to oscillate. The charge controller 46 outputs a charge start signal 46a of level H to the correcting resonance capacitor connection switching means 418 and the digital reference signal generating means 417 (S2). When the output of the regulator 48 exceeds the reference voltage (S3), the correction resonance capacitor connection switching means 418 starts switching the connection of the correction resonance capacitors 43c and 43e to the reference resonance capacitor 43b (S4). When the correcting resonant capacitor connection switching means 418 detects the rising edge of the digital signal 37 (S5), first, after t10, the correction is made based on the count number of the digital reference signal 417a output from the digital reference signal generating means 417. The output 38a of the resonance capacitor connection switching means 418 for level 418 becomes level H and AS1 and 43d are turned on (S6). After t20, the output 39a of the resonance capacitor connection switching means 418 for correction becomes level H and AS2 43f are turned on (S7), and after t11, the output 38a of the correcting resonance capacitor connection switching means 418 becomes level L, AS1 and 43d are turned off (S8), and after t21, the correcting resonance capacitor connection is made. The output 39a of the switching means 418 becomes level L, and AS2 and 43f are turned off (S ). Since the charge controller 46 has not yet issued the level L charge end signal 46a, the process returns to step S5, and when the correcting resonance capacitor connection switching means 418 detects the fall of the digital signal 37 (S5), the digital reference Based on the count number of the digital reference signal 417a output from the signal generating means 417, first, after t10, the output 38b of the correcting resonance capacitor connection switching means 418 becomes the level H, and the AS1 and 43d are turned on (S6). ), After t20, the output 39b of the correcting resonance capacitor connection switching means 418 becomes level H, turns on AS2 and 43f (S7), and after t11, the output 38b of the correcting resonance capacitor connection switching means 418 becomes At level L, AS1 and 43d are turned off (S8). The output 39b of the capacitors connected switching means 418 becomes level L, turning off the AS2,43f (S9). This sequence is repeated, and then, in S10, when the external power oscillation device 42 finishes oscillating and the charge controller 46 outputs a charge end signal 46a of level L, the correcting resonance capacitor switching means 418 makes the reference resonance. Switching of the connection of the correcting resonance capacitors 43c and 43 to the capacitor 43b is stopped (S11), and the wireless charging is finished.

In the flowchart at the time of wireless charging shown in FIG. 2, the overcharge / overdischarge detection signal output means 419 does not operate. When the overcharge / overdischarge detection signal output means 419 outputs an overcharge detection signal 419a of level H to the charge controller 46, the charge controller 46 waits until the overcharge detection signal 419a becomes level L. Stop the charge control function. When the overcharge / overdischarge detection signal output means 419 outputs an overdischarge detection signal 419b of level H to the regulator 48, the regulator 48 keeps the wireless charging device until the overdischarge detection signal 419b becomes level L. The output to 41 outside (output voltages 48a and 48b) is stopped.

In FIG. 1, two correction resonance capacitors 3c and 3e are connected in parallel to the reference resonance capacitor 3b. In FIG. 4, two correction resonance capacitors 43c and 43e are connected to the reference resonance capacitor 43b. Although it is connected in series, it is clear that one or three or more correction resonance capacitors can be used, and it is clear that correction resonance capacitors can be connected in parallel and in series to the reference resonance capacitor, so the description is omitted. To do.

As shown in the above detailed description, by using the wireless charging device of the present invention and the wireless charging method using the same, a mobile phone, a wireless phone in which a metal casing or a part of the casing is metal is used. An electronic device or an electronic device that is charged wirelessly, such as a charging heart pacemaker or an electric vehicle, can be charged more efficiently, or the electronic device or the electronic device can be reduced in size and thickness.

It is a block diagram of the 1st wireless charging device of this invention. It is a flowchart at the time of wireless charging. It is a time change of each signal at the time of wireless charging. It is a block diagram of the 2nd wireless charging device of the present invention. It is a plane arrangement view of the first primary coil of the external power oscillation device used in the present invention and the first resonance coil of the wireless charging device of the present invention. It is a cross-sectional arrangement view of the second primary coil of the external power oscillation device used in the present invention and the second resonance coil of the wireless charging device of the present invention. It is a conventional wireless charging device. It is a plane arrangement view of a primary coil of an external power oscillation device used in the related art and a secondary coil of a conventional wireless charging device. It is a cross-sectional arrangement view of another primary coil of an external power oscillation device used in the related art and another secondary coil of a conventional wireless charging device.

1, 41, 71 Wireless charging devices 2, 42, 72 External power oscillators 2a, 42a, 72a AC power supplies 2b, 42b, 72b Primary capacitors 2c, 32c, 72c Primary coils 3, 43, 73 Resonant circuits 3a, 43a , 73a Resonant coils 3b, 43b, 73b Reference resonant capacitors 3c, 3e, 43c, 43e Correction resonant capacitors 3d, 3f, 43d, 43f Analog switches 4, 44, 74 Full-wave rectifier circuits 4a, 4b, 4c, 4d, 44a , 44b, 44c, 44d,
74a, 74b, 74c, 74d Diode 5, 45, 75 Charging capacitor 6, 46, 76 Charge controller 6a, 46a Charging start end signal 7, 47, 77 Lithium ion secondary battery 8, 48, 78 Regulator 8a, 8b, 48a, 48b, 78a, 78b Regulator output voltage 9, 49, 79 Digital signal generation means 9a, 49a Digitization means 9b, 49b Phase advancement means 17, 417 Digital reference signal generation means 17a, 417a Digital reference signal 18, 418 Correction resonance capacitor connection switching means 19, 419, 79 Overcharge overdischarge detection signal output means 19a, 419a Overcharge detection signals 19b, 419b Overdischarge detection signals 19c, 419c Voltage charge capacity characteristic data

Claims (6)

External power that consists of a resonant capacitor connected in series with each other and a resonant coil that has a closed-loop magnetic core whose partial cross-sectional area of the magnetic core without winding is smaller than the cross-sectional area of the winding part. In the wireless charging device, which includes a resonance circuit that resonates at a frequency of and a secondary battery that charges external power via the resonance circuit, and the casing is made of metal or part of the casing is made of metal, the resonance capacitor includes And a reference resonance capacitor, and one or more correction resonance capacitors that can be connected to the reference resonance capacitor and are used to resonate the resonance circuit to the frequency of the external power. Charging device. The wireless charging apparatus according to claim 1, wherein the correction resonance capacitor is connected in series or in parallel to the reference resonance capacitor by an analog switch, or is disconnected from the reference resonance capacitor. The wireless charging apparatus according to claim 1, wherein the wireless charging apparatus includes a digital reference signal generating unit that generates a digital reference signal having a frequency sufficiently higher than a frequency of the external power. The wireless charging device generates a digital signal by digitizing means for digitizing the voltage between both ends of the resonance coil into a digital voltage having the same frequency as the frequency of the external power, and by advancing its phase by 90 degrees. 4. The wireless charging device according to claim 1, further comprising a digital signal generating means comprising means for advancing the phase by 90 degrees. 5. The wireless charging device according to claim 1, wherein the correction resonance capacitor is connected in parallel to the reference resonance capacitor in response to an increase in the resonance current, or the reference resonance capacitor. Disconnecting the correcting resonant capacitor from the series connection and switching the resonant capacitor to increase its capacitance, and in response to a decrease in the resonant current from the reference resonant capacitor. By disconnecting the correcting resonant capacitor from the parallel connection, or by connecting the correcting resonant capacitor in series to the reference resonant capacitor and switching the resonant capacitor so that its capacitance is reduced, the resonant circuit is A wireless charging method comprising resonating with a frequency of the external power. The 90-degree advancement of the digital voltage by the phase advancement means is performed based on the count number of the digital reference signal output from the digital reference signal generation means, and the switching timing of the resonance capacitor is: The wireless charging method according to claim 5, wherein the wireless charging method is performed based on a count number of the digital reference signal from a rising edge or a falling edge of the digital signal.