JP2014217158A - Non-contact charging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact charging apparatus capable of improving the charging efficiency and capable of handling wide range charging voltage.SOLUTION: The non-contact charging apparatus includes: a charging target apparatus 4 which includes a power receiving circuit 20 with a power receiving coil 6 and a battery charger 19 that charges a rechargeable battery based on the power output from the power receiving circuit 20; a non-contact charging section 3 which includes plural power supply coils 7a-7d capable of magnetic coupling with the power receiving coil 6, plural power supply circuits 11a-11d for supplying excitation current to the power supply coils, and a control circuit 14 that selects high speed charge or low speed charge by selecting the number of power supply circuits for supplying the excitation current power supply coils; and a base table including the non-contact charging section capable of holding the charging target apparatus 4 at a position where the power receiving coil 6 and the power supply coils 7a-7d are magnetic coupled.

Description

  The present invention relates to a non-contact charging device that charges a rechargeable battery of an electric tool equipped with a rechargeable battery or other electric devices in a non-contact state.

  2. Description of the Related Art Conventionally, there has been put into practical use an electric tool that does not have a power cord for supplying commercial power but is designed to operate using a built-in rechargeable battery as a power source. Such a power tool generally has a configuration in which a rechargeable battery is charged by electrically connecting a charging terminal of a charging device to a metal contact provided on a main body of the power tool.

As described above, in the configuration in which the rechargeable battery and the charging device are electrically connected via the mechanical contact and charged, charging failure due to contamination of the contact, electrostatic breakdown of the charging device, or the like may occur. is there.
In recent years, a rechargeable battery can be charged in a contactless manner without requiring a mechanical contact by magnetically coupling a power supply coil provided on the charging device side and a power receiving coil provided on the power tool side. Charging devices have been put into practical use.

Patent Literature 1 discloses an electric tool including a battery pack that can be charged via a mechanical contact and charged in a non-contact manner.
Patent Document 2 discloses an electric tool that can supply electric power without contact.

Patent Document 3 discloses a charging device including a low output circuit for continuously charging a secondary battery and a quick charging circuit for rapid charging.
Patent Document 4 discloses a method for charging a battery pack of a mobile device that enables normal charging and quick charging.

  Patent Document 5 discloses a charging method including switching means for switching between a rated quick charge and a limited quick charge according to a charge start voltage for a general secondary battery.

JP 2011-34793 A JP 2005-73350 A Japanese Utility Model Publication No. 62-68427 JP 2007-52968 A JP 2001-186683 A

  In the non-contact charging device as described above, for example, since there is one power receiving coil provided on the electric tool side and one power feeding coil provided on the charging device side, the relative position between the power feeding coil and the power receiving coil during the charging operation If it is shifted, the charging efficiency decreases.

Therefore, the configuration for installing the electric tool at an appropriate position with respect to the charging device during charging and the operation thereof become complicated.
In addition, since there is one feeding coil and one receiving coil, it is difficult to switch the charging voltage in multiple steps and in a wide range.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a non-contact charging apparatus capable of improving charging efficiency and supporting a wide range of charging voltages.

  A contactless charging apparatus that solves the above problems includes a power receiving circuit including a power receiving coil, a charged device including a charger that charges a rechargeable battery based on output power of the power receiving circuit, the power receiving coil, and a magnetic device. Select a plurality of power supply coils that can be coupled, a plurality of power supply circuits that supply an excitation current to the power supply coil, and a number of power supply circuits that supply the excitation current to the power supply coil to select high-speed charging and low-speed charging A non-contact charging unit including a control circuit, and a base including the non-contact charging unit and capable of holding the charged device at a position where the power receiving coil and the power feeding coil of the charged device are magnetically coupled. It is characterized by having.

  Further, in the above configuration, the contactless charging unit includes a voltage detection circuit that outputs a detection voltage based on an interval between each of the power feeding coils and the power receiving coil, and the control circuit is based on the detection voltage during low-speed charging. Therefore, it is preferable to supply the exciting current to the power feeding coil having a small distance from the power receiving coil.

In the above configuration, it is preferable that the control circuit selects the number of the power feeding circuits to be operated simultaneously according to the remaining voltage of the rechargeable battery.
In the above configuration, it is preferable that the control circuit supplies excitation currents having different phases at the same frequency to each of the power supply coils when simultaneously driving the plurality of power supply circuits.

In the above configuration, it is preferable that the plurality of power feeding coils can be installed at the same interval with respect to the power receiving coil of the device to be charged held on the base.
In the above configuration, it is preferable that the power receiving circuit includes a switching device that switches a resonance frequency of the power receiving coil.

  According to the non-contact charging apparatus of the present invention, charging efficiency can be improved and a wide range of charging voltages can be handled.

It is a perspective view which shows a non-contact charging device. It is a perspective view which shows a receiving coil. It is a side view which shows a receiving coil and a feeding coil. (A) and (b) are perspective views which show the core of a feeding coil. It is a block diagram which shows the electric constitution of a non-contact charging device. It is explanatory drawing which shows the detection voltage detected with an electric power feeding circuit. It is a circuit diagram which shows a power feeding circuit and a power receiving circuit. It is a timing waveform diagram which shows operation | movement of the control circuit of 1st embodiment. It is an output voltage characteristic view of the power receiving circuit of the first embodiment. It is an output electric power characteristic figure of the receiving circuit of 1st embodiment. It is a timing waveform diagram which shows operation | movement of the control circuit of 2nd embodiment. It is an output voltage characteristic view of the power receiving circuit of the second embodiment. It is an output electric power characteristic figure of the power receiving circuit of 2nd embodiment. It is a timing waveform diagram which shows operation | movement of the control circuit of 3rd embodiment. It is an output voltage characteristic view of the power receiving circuit of the third embodiment. It is an output electric power characteristic figure of the power receiving circuit of 3rd embodiment.

(First embodiment)
Hereinafter, a first embodiment of a non-contact charging apparatus will be described with reference to FIGS.
The non-contact charging apparatus shown in FIG. 1 is provided with a non-contact charging unit 3 on one end side of a base 2 of a main body case 1, and a grip unit 5 on the base end side of a tool 4 can be inserted into the non-contact charging unit 3. It has become. The tool 4 is a rechargeable drill driver in this embodiment.

As shown in FIG. 2, a power receiving coil 6 is disposed in the grip portion 5. The power receiving coil 6 is disposed in a direction in which the axial center thereof coincides with the axial center of the grip portion 5.
As shown in FIG. 3, in the contactless charging unit 3, four power supply coils 7 a to 7 d are arranged around the grip unit 5 at equal intervals along the circumferential direction of the grip unit 5. .

  As shown in FIG. 4A, each of the feeding coils 7a to 7d is formed by winding a wire 9 around a plate-shaped core 8, and the axis of each of the feeding coils 7a to 7d and the receiving coil 6 is parallel. It is arranged to become.

  When an excitation current having a preset frequency is supplied to at least one of the feeding coils 7 a to 7 d, an electromagnetic induction current is generated in the receiving coil 6 based on the magnetic coupling between the feeding coils 7 a to 7 d and the receiving coil 6. Occur. Based on this electromagnetic induction current, the rechargeable battery built in the tool 4 is charged.

Next, the electrical configuration of the non-contact charging apparatus as described above will be described.
As shown in FIG. 5, the contactless charging unit 3 of the main body case 1 includes a power supply circuit 10, first to fourth power supply circuits 11a to 11d, a voltage detection circuit 12, a signal processing circuit 13, a control circuit 14, and a drive. A circuit 15 is provided.

  In the power supply circuit 10, a DC power supply voltage Vd is generated based on the supply of the commercial power supply AC, and the DC power supply voltage Vd is the first to fourth power supply circuits 11 a to 11 d, the voltage detection circuit 12, the signal processing circuit 13, It is supplied to the control circuit 14 and the drive circuit 15.

  The first to fourth power supply circuits 11a to 11d have a function of generating a high frequency excitation signal based on the DC power supply voltage Vd supplied from the power supply circuit 10 and supplying the high frequency excitation signal to the power supply coils 7a to 7d, respectively. Based on the drive signal from the drive circuit 15, a high frequency excitation signal is supplied to the power supply coils 7a to 7d.

The voltage detection circuit 12 detects the detection voltage output from the first to fourth power feeding circuits 11 a to 11 d and outputs the detection voltage to the signal processing circuit 13.
When the first to fourth power feeding circuits 11a to 11d are not generating a high frequency excitation signal, the power feeding coil determines whether or not the power receiving coil 6 is present in the contactless charging unit 3 and the distance from the power receiving coil 6. Detection is performed based on the mutual inductance between 7 a to 7 d and the power receiving coil 6, and the detected voltage is output to the voltage detection circuit 12.

  As shown in FIG. 6, detection voltages Vdet1 and Vdet2 are detected according to the size of the distance between each of the power feeding coils 7a to 7d and the power receiving coil 6, and the larger the distance between the power feeding coils 7a to 7d and the power receiving coil 6 is. The detection voltages Vdet1 and Vdet2 are increased. In the figure, the power supply coil connected to the power supply circuit that detects the detection voltage Vdet1 has a larger distance from the power reception coil than the power supply coil connected to the power supply circuit that detects the detection voltage Vdet2.

Further, when the tool 4 is not placed on the contactless charging unit 3, the power supply circuits 11a to 11d detect the detection voltage Vdet3 higher than the detection voltages Vdet1 and Vdet2.
The detection voltage detected for each of the power supply coils 7 a to 7 d is output from the voltage detection circuit 12 to the signal processing circuit 13. The signal processing circuit 13 compares the preset threshold value Vt with the input detection voltage to detect the presence or absence of the power receiving coil 6 in the contactless charging unit 3 and when the power receiving coil 6 is present. Detects the size of the interval between each of the power feeding coils 7 a to 7 d and the power receiving coil 6 and outputs the detected magnitude to the control circuit 14.

  For example, if the detection voltage detected by each of the power supply circuits 11a to 11d is the detection voltage Vdet3 that is higher than the threshold value Vt, it is detected that the tool 4 is not placed on the contactless charging unit 3. . Further, if the detection voltage detected by each of the power supply circuits 11a to 11d is a detection voltage lower than the threshold value Vt, the size of the interval between each of the power supply coils 7a to 7d and the power reception coil 6 is detected, and these detection signals are detected. Is output to the control circuit 14.

  The control circuit 14 is formed by a microcomputer that operates based on a preset program, and the first to fourth power feeds via the drive circuit 15 based on a detection signal output from the signal processing circuit 13. All or some of the circuits 11a to 11d are selected and driven.

  The grip portion 5 includes a power receiving circuit 20 including the power receiving coil 6. When the grip part 5 of the tool 4 is placed on the contactless charging part 3, the power supply coils 7a to 7d and the power reception coil 6 form a magnetic coupling circuit, and at least one of the power supply coils 7a to 7d is excited. When a current is supplied, an induced current is generated in the power receiving coil 6.

  The power receiving coil 6 is connected to a matching circuit 16. The matching circuit 16 includes a capacitor that forms a resonance circuit together with the power receiving coil 6, and outputs an alternating current signal centered on the resonance frequency to the rectifying and smoothing circuit 17.

The rectifying / smoothing circuit 17 rectifies and smoothes the alternating current output from the matching circuit 16 to generate a direct current, and outputs the direct current to the output voltage stabilizing circuit 18.
The output voltage stabilizing circuit 18 converts the direct current output from the rectifying and smoothing circuit 17 to a constant current and outputs the constant current to the charger 19. The charger 19 charges the rechargeable battery with the supplied constant current. The charger 19 can detect the remaining voltage of the rechargeable battery and output a voltage detection signal corresponding to the remaining voltage to the control circuit 14 via a photocoupler.

Next, specific configurations of the first to fourth power feeding circuits 11a to 11d and the power receiving circuit 20 will be described.
As shown in FIG. 7, since the first to fourth power supply circuits 11a to 11d have the same configuration, only the first power supply circuit 11a will be described. The DC power supply voltage Vd supplied from the power supply circuit 10 is supplied to the drains of the N-channel MOS transistors T1 and T2, and the sources of the transistors T1 and T2 are connected to the drains of the N-channel MOS transistors T3 and T4, respectively. . The sources of the N channel MOS transistors T3 and T4 are connected to the ground GND.

Between the source / drain of the transistors T1, T3 and the source / drain of the transistors T2, T4, the feeding coil 7a and the capacitor C1 are connected in series.
Drive signals A and B are input from the drive circuit 15 to the gates of the transistors T1 to T4. Then, the in-phase drive signal A is input to the transistors T1 and T4, and the in-phase drive signal B is input to the transistors T2 and T3.

  As shown in FIG. 8, the drive signals A and B are signals that alternately become H level at a preset frequency, and the transistors T1 and T4 and the transistors T2 and T3 are alternately turned on.

By such an operation, an exciting current having a preset frequency is supplied to the feeding coil 7a.
The second to fourth power supply circuits 11b to 11d have the same configuration, and in this embodiment, the drive signals A and B supplied to the power supply circuits have the same frequency and the same phase.

  In the power receiving circuit 20, the power receiving coil 6 is connected to a matching circuit 16. In the matching circuit 16, a plurality of capacitors C2 to C4 are connected in parallel to one end of the power receiving coil 6 via switch elements T5 to T7, respectively. The capacitors C2 to C4 have different capacities, and are set to 1 nF, 50 nF, and 120 nF, for example.

  Each of the switch elements T5 to T7 is composed of, for example, a phototransistor, and the switch element T5 to T7 is operated by the operation of a photocoupler element provided in the contactless charging unit based on a selection signal output from the drive circuit 15. ON / OFF operation is controlled.

  Therefore, by selecting any one of the switch elements T5 to T7 and making them conductive, the capacitors C2 to C4 connected to the power receiving coil 6, that is, the capacitance value is adjusted, and either the power receiving coil 6 or the capacitors C2 to C4 are used. The set resonance frequency can be adjusted.

  The alternating current output from the matching circuit 16 is smoothed by a rectifying / smoothing circuit 17 including a full-wave rectifier circuit and a capacitor C5, and output to the output voltage stabilizing circuit 18. The output voltage stabilization circuit 18 supplies a constant current to the charger 19 by the operation of the NPN transistor whose base voltage is constant.

Next, the operation of the non-contact charging apparatus configured as described above will be described.
When the rechargeable battery built in the grip portion 5 is charged at high speed with the grip portion 5 of the tool 4 inserted into the non-contact charging portion 3 of the base 2, that is, the voltage level at which the remaining voltage of the rechargeable battery is set in advance. If lower, the control circuit 14 operates all of the first to fourth power feeding circuits 11a to 11d through the driving circuit 15 with the same frequency and the same phase.

  Then, an exciting current flows through each of the power feeding coils 7a to 7d, and an induced current is generated in the power receiving coil 6 of the power receiving circuit 20 based on the exciting current. Then, the direct current generated through the matching circuit 16, the rectifying / smoothing circuit 17, and the output voltage stabilizing circuit 18 based on the induced current is supplied to the charger 19, and the rechargeable battery is charged.

  In such a high-speed charging operation, the output voltage induced in the power receiving coil 6 increases and the induced current increases due to the magnetic coupling of the four power feeding coils 7a to 7d and the power receiving coil 6. Therefore, the charging time of the rechargeable battery is shortened.

  On the other hand, when the remaining voltage of the rechargeable battery is higher than a preset voltage level, the low speed charging is selected by the control circuit 14, and any one of the first to fourth power feeding circuits 11a to 11d is selected and driven. Is done.

  At this time, as shown by a chain line in FIG. 3, when the power receiving coil 6 is shifted to the power feeding coil 7 a side due to the shift of the mounting position of the grip portion 5, the control circuit 14 has first to fourth. The detection voltage output from the power supply circuits 11 a to 11 d to the voltage detection circuit 12 detects that the power supply coil 7 a is closest to the power reception coil 6. Then, low-speed charging is performed by driving only the first power supply circuit 11a and supplying an excitation current only to the power supply coil 7a.

When the rechargeable battery is charged to a preset voltage, the control circuit 14 ends the charging operation.
For example, if the distance between the two power supply coils and the power reception coil 6 is substantially the same, either one of the power supply coils is selected based on a preset program and an exciting current is supplied.

In addition to the selection of high-speed charging and low-speed charging, the output voltage of the power receiving circuit 20 can be adjusted stepwise by appropriately selecting the number of power feeding circuits driven by the control circuit 14.
FIG. 9 shows the output voltage Vo1 of the power receiving circuit 20 when one power feeding circuit is selected and driven from the first to fourth power feeding circuits 11a to 11d, and the case where two power feeding circuits are selected and driven. The output voltage Vo2 of the power receiving circuit 20 is shown. In addition, the numerical value when the load of the power receiving circuit 20 is 100Ω is shown.

  As shown in the figure, when the power feeding circuit is driven at 75 kHz, the output voltage Vo1 of the power receiving circuit 20 when only one power feeding circuit is driven is about 40 V, whereas the two power feeding circuits are driven. In this case, the output voltage Vo2 of the power receiving circuit 20 is about 75V.

  Further, as shown in FIG. 10, the output power of the power receiving circuit 20 under the same conditions as described above is about 16 W when driving only one power feeding circuit, whereas two power feeding circuits are used. The output power Wo2 when driving is about 56W.

In the non-contact charging apparatus as described above, the following effects can be obtained.
(1) Since a plurality of power supply coils 7a to 7d can be magnetically coupled to the power receiving coil 6 to generate an induced voltage in the power receiving coil 6, the output voltage and output power of the power receiving circuit 20 can be improved. .
(2) The output voltage and output power of the power receiving circuit 20 can be adjusted by selecting the number of power supply coils that supply the excitation current.
(3) By selecting the number of feeding coils that supply the exciting current, the rechargeable battery charged by the power receiving circuit 20 can be charged at high speed or low speed.
(4) When one feeding coil is selected from the four feeding coils 7a to 7d during low-speed charging, based on the detection voltage output from the first to fourth feeding circuits 11a to 11d to the voltage detection circuit, An exciting current can be supplied by selecting a feeding coil located closest to the power receiving coil. Therefore, even when the grip portion 5 of the tool 4 is deviated from the normal charging position in the contactless charging portion 3, the low-speed charging operation can be performed efficiently.
(5) The output voltage and output power of the power receiving circuit 20 can be adjusted in four stages by appropriately adjusting the number of feeding coils that supply the excitation current between one and four. Therefore, it is possible to cope with the charging operation of tools having different charging voltages.
(Second embodiment)
11 to 13 show a second embodiment. In this embodiment, in addition to the function of the control circuit 14 of the first embodiment, a function of exciting a feeding coil to be selectively excited with excitation currents having different phases is added. Since the electrical configurations of the contactless charging unit 3 and the tool 4 are the same as those in the first embodiment, the same reference numerals are used for explanation.

  As shown in FIG. 11, for example, when the first power supply circuit 11a and the second power supply circuit 11b are driven and the exciting current is supplied to the power supply coils 7a and 7b, the first power supply circuit 11a and the second power supply circuit are supplied. Driving signals A and B having different phases having a phase difference Px are supplied to the circuit 11b.

  FIG. 12 shows the output voltage Vo3 of the power receiving circuit 20 when the two power feeding circuits are driven by the driving signals A and B having different phases. In addition, the numerical value when the load of the power receiving circuit 20 is 100Ω is shown.

  As shown in the figure, when the power feeding circuit is driven at 75 kHz, the output voltage Vo3 of the power receiving circuit 20 is changed to 0 to 75 V when the phase difference between the drive signals supplied to the two power feeding circuits is changed to 0 to 7 μs. It becomes possible to control within the range.

Further, as shown in FIG. 13, the output power Wo3 of the power receiving circuit 20 under the same conditions as described above can be controlled in the range of 0 to 60W.
In the non-contact charging apparatus as described above, the following effects can be obtained in addition to the effects obtained in the first embodiment.
(1) The output current and output power of the power receiving circuit 20 can be adjusted by adjusting the phase of the excitation current supplied to the plurality of power supply coils.
(2) In addition to the adjustment of the number of power supply coils that supply the excitation current, the output voltage and output power of the power receiving circuit 20 are adjusted by adjusting the phase of the excitation current supplied to two or more power supply coils. In addition to the stepwise adjustment by adjusting the number of the signals, it is possible to adjust continuously by adjusting the phase.
(Third embodiment)
14 to 16 show a third embodiment. In this embodiment, in addition to the function of the control circuit 14 of the first embodiment, any one of the capacitors C2 to C4 of the matching circuit 16 is selected and the resonance frequency with the power receiving coil 6 is changed, thereby receiving power. The output voltage and output power of the circuit 20 are adjusted. Since the electrical configurations of the contactless charging unit 3 and the tool 4 are the same as those in the first embodiment, the same reference numerals are used for explanation.

  As shown in FIG. 14, when the selection signal S1 is output from the control circuit 14, the switch element T5 becomes conductive, and a capacitor C2 having a capacitance value of 1 nF is provided between the power receiving coil 6 and the full-wave rectifier circuit. Connected.

  Similarly, when the selection signal S2 is output from the control circuit 14, the switch element T6 becomes conductive, and the capacitor C3 having a capacitance value of 50 nF is connected between the power receiving coil 6 and the full-wave rectifier circuit. It becomes.

  When the selection signal S3 is output from the control circuit 14, the switch element T7 becomes conductive, and the capacitor C4 having a capacitance value of 120 nF is connected between the power receiving coil 6 and the full-wave rectifier circuit. Become.

  FIG. 15 shows output voltages Vo4 and Vo5 when the capacitor connected to the power receiving coil 6 is switched when an exciting current is supplied to one or two power feeding coils. In addition, the numerical value when the load of the power receiving circuit 20 is 100Ω and the exciting current frequency of each feeding coil is 75 kHz is shown.

When the capacitors C2 to C4 are switched when exciting one power supply coil, the output voltage Vo4 changes to 2v, 35V, and 41V.
Further, when the capacitors C2 to C4 are switched when two power supply coils are excited, the output voltage Vo5 changes to 3v, 62V, and 75V.

Also, as shown in FIG. 16, the output power Wo4 of the power receiving circuit 20 when one power supply coil is excited under the same conditions as described above is 0 W, 10 W, and 17 W.
When the two power supply coils are excited, the output power Wo5 of the power receiving circuit 20 is 0 W, 38 W, and 56 W.

In the non-contact charging apparatus as described above, the following effects can be obtained in addition to the effects obtained in the first embodiment.
(1) The output voltage and output power of the power receiving circuit 20 can be adjusted by switching the capacitance of the capacitor connected to the power receiving coil 6 and adjusting the resonance frequency.
(2) In addition to the adjustment of the number of power supply coils that supply the excitation current, the output voltage and output power of the power reception circuit 20 are adjusted stepwise by adjusting the number of power supply coils by adjusting the resonance frequency of the power reception coil 6. In addition to the simple adjustment, the resonance frequency can also be adjusted.

In addition, you may change the said embodiment as follows.
-As shown in FIG.4 (b), the core 8 of a feed coil is good also as a semi-cylinder shape.
-It can also be used privately as a non-contact charging device for electrical equipment other than electric tools.・

  DESCRIPTION OF SYMBOLS 1 ... Main body case, 2 ... Base, 3 ... Non-contact charge part, 4 ... Charged apparatus (tool), 6 ... Power receiving coil, 7a-7d ... Feed coil, 11a-11d ... Feed circuit, 12 ... Voltage detection circuit , 14 ... control circuit, 19 ... charger, 20 ... power receiving circuit, C2-C4 ... switching device, T5-T7 ... switching device (switch element).

Claims (6)

A power receiving circuit including a power receiving coil;
A to-be-charged device comprising a charger for charging a rechargeable battery based on the output power of the power receiving circuit;
A plurality of power supply coils that can be magnetically coupled to the power reception coil;
A plurality of power supply circuits for supplying an excitation current to the power supply coil;
A non-contact charging unit including a control circuit that selects a fast charging and a slow charging by selecting the number of the feeding circuits that supply the exciting current to the feeding coil;
A non-contact charging apparatus comprising: the non-contact charging unit; and a base that can hold the device to be charged at a position where the power receiving coil and the power feeding coil of the device to be charged are magnetically coupled. The contactless charging device according to claim 1,
The contactless charging unit is
A voltage detection circuit that outputs a detection voltage based on the interval between each of the power supply coils and the power reception coil;
The non-contact charging apparatus, wherein the control circuit supplies an exciting current to a power feeding coil having a small distance from the power receiving coil based on the detected voltage during low-speed charging. In the non-contact charging device according to claim 1 or 2,
The control circuit includes:
The non-contact charging apparatus, wherein the number of the feeding circuits that are operated simultaneously is selected according to the remaining voltage of the rechargeable battery. In the non-contact charging device according to claim 1 or 3,
When the plurality of power supply circuits are driven simultaneously, the control circuit supplies excitation currents of different phases at the same frequency to each of the power supply coils. In the non-contact charging device according to any one of claims 1 to 4,
The non-contact charging apparatus, wherein the plurality of power feeding coils can be installed at the same interval with respect to a power receiving coil of a device to be charged held on the base. In the non-contact charging device according to any one of claims 1 to 5,
The non-contact charging device, wherein the power receiving circuit includes a switching device that switches a resonance frequency of the power receiving coil.