JPH0879976A - Non-contact type charger - Google Patents

Abstract

PURPOSE: To rapidly charge a secondary battery by improving the power transmission efficiency from a charging part to a part to be charged in a non-contact type charger. CONSTITUTION: In a non-contact type charger where a charging part and a part to be charged are separated, the charging part is provided with an oscillation circuit including a parallel resonance circuit consisting of a transmission side coil 15 and a capacitor 29 for resonance, the part to be charged is provided a reception side coil 16 for inducing voltage while it is electromagnetically connected to the transmission side coil 15 of an oscillation circuit on charging and a secondary battery 18 which is charged by a voltage which is induced at the reception side coil 16, a capacitor 34 for resonance is connected in parallel with the reception side coil 16 at the part to be charged and a parallel resonance circuit is provided. Also, in the part to be charged, an electromagnetic shielding plate 17 for shielding electromagnetic field generated at the charging part is laid out between the reception side coil 16 and the secondary battery 18 for constituting the parallel resonance circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric shaver (electric shaving device), a cordless telephone, an electric toothbrush, a laptop personal computer, and other various electric devices or electronic devices using a rechargeable secondary battery as a power source. The present invention relates to a non-contact type charger used for the above.

In particular, the present invention relates to a non-contact type charger which can charge a charged part having a secondary battery in a non-contact manner with a charging part having an oscillation circuit for charging.

[0003]

2. Description of the Related Art FIG. 8 is an explanatory view of a conventional example. In FIG.
1 is a stand, 2 is a power plug, 3 is a toothbrush handle, 4
Is a power cord, 5 is a secondary battery, L₁, L₂Is a primary carp
Le, L₃Is the secondary coil, D₁, D₂Is a diode, T_r
Is a transistor, C₁, C₂, C ₃Is a capacitor, R₁
Indicates resistance.

Conventionally, for example, a device shown in FIG. 8 has been known as a non-contact type device having a charging part and a charged part (see Japanese Utility Model Laid-Open No. 60-8636). This device is an example of an electric toothbrush, and the stand 1 has a charging part and the handle 3 of the toothbrush has a charged part.

In the charging section of the stand 1, a high frequency oscillator (self-excited oscillation circuit) composed of the primary coils L ₁ and L ₂ of the transformer, the transistor _Tr , the resistor R ₁ , and the capacitors C ₂ and C ₃ is provided. ), And is configured to generate an electromagnetic field from the high frequency oscillation circuit to the outside.

Further, a secondary coil L ₃ of the transformer is electromagnetically coupled to the charged portion of the handle 3 of the toothbrush with the primary coils L ₁ and L _{2 of the} charging portion to induce a voltage. A diode D ₂ for rectification and a secondary battery (Ni
-Cd battery) 5 and the like are provided.

When using the electric toothbrush, a person takes the handle 3 of the toothbrush and takes it out from the stand 1 and uses it.

In this storage state, the primary coil of the charging section
L₁, L₂And the secondary coil L of the part to be charged ₃Is electromagnetically coupled
The secondary coil L of the part to be charged.₃Voltage is induced in
It Then, due to this induced voltage, the diode D₂To
The secondary battery 5 is charged via the battery.

[0009]

SUMMARY OF THE INVENTION The above-mentioned conventional device has the following problems. Primary coil L
₁ , ₁ and L ₂ are stored in the charging part of the stand 1, and the secondary coil L ₃ is stored in the charged part of the handle 3 of the toothbrush.
Then, the handle 3 of the toothbrush is configured to be charged while being housed inside the cylinder of the stand 1.

In this case, the stand 1 and the handle 3 of the toothbrush
In order to prevent the internal circuit components from getting wet with water, it has a watertight structure integrally formed with resin, for example. Therefore, there is the thickness of the resin portion outside the handle 3 of the toothbrush and the thickness of the resin portion that constitutes the housing of the stand 1, and the distance between the primary and secondary coils increases accordingly.

Therefore, the degree of coupling between the primary and secondary coils becomes small, and the charging current to the charging secondary battery becomes extremely small. As a result, the secondary battery for charging cannot be rapidly charged in a short time.

The present invention solves such a conventional problem and improves the power transmission efficiency from the charging section to the charged section in the non-contact type charger, thereby enabling the rapid charging of the secondary battery. The purpose is to do.

[0013]

FIG. 1 is a diagram for explaining the principle of the present invention. In order to achieve the above-mentioned object, the present invention is configured such that a charging part and a charged part are separated from each other, and the charging part includes an oscillation circuit including a parallel resonance circuit including a transmission side coil 15 and a resonance capacitor 29 ( A high-frequency oscillator circuit), and the portion to be charged has a coil 15 on the transmission side of the oscillator circuit during charging.
Receiving side coil 1 for electromagnetically coupling with and inducing a voltage
6 and a non-contact type charger including a secondary battery 18 that can be charged by a voltage induced in the receiving coil 16 by connecting a resonance capacitor 34 in parallel with the receiving coil 16 of the part to be charged. A parallel resonant circuit was constructed.

Further, in the part to be charged, an electromagnetic shield plate 17 for shielding the electromagnetic field generated in the charging part is arranged between the receiving coil 16 and the secondary battery 18 which form a parallel resonance circuit. did.

[0015]

The operation of the present invention based on the above construction will be described with reference to FIG. When the secondary battery 18 is charged, the power is turned on with the charged part placed on the charging part. In this charging state, the transmission side coil 15 and the reception side coil 16 are arranged so as to face each other, and thus these coils function similarly to the coils of the transformer. That is, the transmitting coil 15 functions as the primary winding of the transformer, and the receiving coil 16 functions as the secondary coil of the transformer.

When the oscillation circuit of the charging section oscillates during charging,
The parallel resonance circuit forming the oscillation circuit is in a state of resonating at a predetermined frequency. At this time, the transmission side coil 15 and the reception side coil 16 are electromagnetically coupled, the magnetic flux generated in the transmission side coil 15 is linked to the reception side coil 16, and a voltage is induced in the reception side coil 16.

Due to this induced voltage, the receiving coil 1
6 and the capacitor 34 for resonance, the parallel resonance circuit of the charged portion resonates, and the output of this parallel resonance circuit recharges the secondary battery 18
To charge. That is, at the time of charging, the parallel resonant circuit of the charging section and the parallel resonant circuit of the charged section resonate simultaneously to charge the secondary battery 18.

As described above, even if the charging current becomes large due to the resonance of the parallel resonant circuit in the part to be charged,
The terminal voltage of the secondary battery can be maintained at a large value. For this reason,
The secondary battery can be rapidly charged.

In particular, when the capacitance value of the resonance capacitor 34 becomes large, the charging current to the secondary battery 18 and the terminal voltage of the secondary battery become extremely large, and a large current can flow to the secondary battery 18 in a short time. This makes it possible to perform efficient and quick charging.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. In addition, the embodiment described below is an example applied to a non-contact rechargeable electric shaver.

2 to 7 are views showing an embodiment of the present invention. In FIGS. 2 to 7, 10 is a charging section stand, 11 is a charging section stand housing, 12 is an electric shaver, and 13
Is an electric shaver housing, 14 is a printed board, 15
Is a coil on the transmitting side, 16 is a coil on the receiving side, 17 is an electromagnetic shielding plate, 18 is a secondary battery, 19 is a ferrite core, 20 is an electric shaver mount, 22 is a power plug, 23 is a fuse, and 24 is full-wave rectification. Circuit, 25 is a smoothing capacitor, 2
6 is an oscillation capacitor, 27 is a switching transistor, 28 is a starting resistor, 29 is a resonance capacitor, 30
Is a feedback coil, 34 is a resonance capacitor, 35 is a smoothing capacitor, 36 is a rectifying diode, 37 is a constant current element, 38 is an ammeter, 39 is a voltmeter, 41 and 42 are switching transistors, and 43 is a choke. Coil, 4
4, 45 are start-up resistors, 46 is the first transmitting coil, 47
Is a second transmitting coil, 49 is a first receiving coil, 5
Reference numeral 0 represents a second receiving side coil, and 51 represents a smoothing choke coil.

§1: Description of non-contact type rechargeable electric shaver ... See FIGS. 2 and 3. FIG. 2 is an explanatory view 1 of a non-contact rechargeable electric shaver. FIG. It is a top view. 3 is an explanatory view 2 of the non-contact type rechargeable electric shaver. FIG. 3A is a sectional view in the XY direction of FIG. 2, and FIG. 3B is a partially enlarged view of FIG.

The non-contact type rechargeable electric shaver of this embodiment comprises an electric shaver 12 and a charging unit stand 10. The charging unit stand 10 is provided with a charging unit, and the electric shaver 12 is provided with a charged unit.

The charging section stand 10 is provided with a charging section stand housing 11, and the charging section is provided in the charging section stand housing 11. The electric shaver 12 is provided with an electric shaver housing 13,
A portion to be charged is provided in the electric shaver housing 13.

Further, the charging unit stand housing 11
An electric shaver mounting portion 20 for mounting the electric shaver 12 is provided on a part of the above. When the electric shaver 12 is used, the electric shaver mounting portion 20
The electric shaver 12 is taken out from the electric shaver 12 and used, otherwise the electric shaver 12 is used.
It is configured to be charged in a non-contact manner by being placed on the battery pack 0.

The charging part provided in the charging part stand housing 11 is provided with circuit parts such as a high frequency oscillation circuit for charging. These circuit parts are printed board 14
Mounted on. Then, of the circuit components, the transmitting coil 15 is mounted on the printed board 14 in a state of being wound around the ferrite core 19.

In this case, the transmission side coil 15 wound around the ferrite core 19 is arranged at a position facing the electric shaver mounting portion 20 and at a position closest to the electric shaver mounting portion 20.

The charged portion provided in the electric shaver housing 13 is provided with a parallel resonant circuit of a coil and a capacitor. The receiving side coil 16 constituting the parallel resonant circuit is provided inside the electric shaver housing 13. It is provided. In addition, in the electric shaver housing 13,
An electromagnetic shielding plate 17, a secondary battery 18, etc. are provided.

In this case, the receiving side coil 16 is arranged so as to be closest to the electric shaver placing part 20 with the electric shaver 12 placed on the electric shaver placing part 20, and the transmitting side coil 16 is arranged. It is positioned and arranged so as to face 15.

Further, the secondary battery 18 is the electric shaver 1
2 is placed on the electric shaver placing portion 20 at a position far from the electric shaver placing portion 20, and the electromagnetic shielding plate 17 is placed between the receiving side coil 16 and the secondary battery 18, The electromagnetic shielding from the transmission side coil 15 is performed.

When the electromagnetic shielding plate 17 is not provided, the electromagnetic field generated in the transmitting coil 15 reaches the secondary battery 18,
Eddy current flows in the metal body of the secondary battery 18. As a result, 2
The secondary battery may generate heat and the secondary battery may deteriorate. However, by providing the electromagnetic shield plate 17, it is possible to shield the electromagnetic field generated in the transmitting coil 15 and prevent the secondary battery 18 from generating heat.

As the secondary battery, for example, a nickel-cadmium battery, a nickel-hydrogen battery, a lithium-ion battery or the like can be used. In addition, the electromagnetic shield 17
Is composed of, for example, composite ferrite (composite of ferrite and resin).

Further, as shown in FIG. 3B, during charging, between the receiving side coil 16 and the transmitting side coil 15,
There are thicknesses and the like of the charging unit stand housing 11 and the electric shaver housing 13. Therefore, the receiving coil 1
A gap length L _g exists between 6 and the transmitting coil 15.

§2: Description of Circuit Configuration of Charging Section and Charged Section ... See FIG. 4 FIG. 4 is an explanatory diagram of the charging circuit, FIG. 4A is a circuit configuration diagram of the charging section, and FIG. The circuit block diagram of a part is shown.

(1): Description of Circuit Configuration of Charging Section The charging section in the electric shaver 12 is provided with a circuit having the configuration shown in FIG. 4A. This circuit includes a fuse 23, a full-wave rectifier circuit 24, a smoothing capacitor 25, an oscillation capacitor 26, a switching transistor 27,
Starting resistor 28, resonance capacitor 29, transmitting coil 1
It is composed of 5.

In the above-mentioned circuit, the circuit including the fuse 23, the full-wave rectifier circuit 24, and the smoothing capacitor 25 is a circuit that constitutes the power supply section, and full-wave rectifies the commercial frequency AC input from the power plug 22. , A circuit for generating a DC voltage at the terminals of the smoothing capacitor 25.

The circuit including the oscillation capacitor 26, the resonance capacitor 29, the starting resistor 28, the switching transistor 27, and the transmission side coil 15 constitutes a collector tuning type self-excited oscillation circuit. 1
5 and the resonance capacitor 29 form a parallel resonance circuit. In this case, the oscillation circuit is configured to oscillate at the resonance frequency of the parallel resonance circuit.

The transmitting side coil 15 and the feedback coil 30
Are coils wound around ferrite cores (see FIG. 3). In this case, the transmitter coil 15 functions as the primary winding of the transformer during charging, and the feedback coil 30 functions as the feedback winding of the transformer.

(2): Description of Circuit Configuration of Charged Part The chargeable part provided in the electric shaver housing 13 of the electric shaver 12 is provided with a circuit having the structure shown in FIG. 4B.

This circuit is composed of the receiving coil 16, the resonance capacitor 34, the smoothing capacitor 35, the rectifying diode 36, and the constant current element 37. The secondary battery 18 is formed by these circuits. It is configured to charge.

In the above circuit, a resonance capacitor 34 is connected in parallel to the receiving side coil 16, and these constitute a parallel resonance circuit. In this case, the receiving side coil 16 is configured to be electromagnetically coupled to the transmitting side coil 15 of the charging unit during charging. Therefore, at the time of charging, a voltage is induced in the receiving side coil 16, and the parallel resonant circuit resonates by the induced voltage.

§3: Description of Operation of Charging Circuit The charging operation of the charging section and the charged section is as follows. (1): Outline of operation When charging the secondary battery, as shown in FIGS. 2 and 3, with the electric shaver 12 mounted on the electric shaver mounting portion 20 of the charging unit stand 10. Turn on the power and perform.

In this charging state, the transmitting side coil 15 and the receiving side coil 16 are arranged so as to face each other, so that these coils function similarly to the primary coil and the secondary coil of the transformer. That is, the transmitting coil 15 functions as a primary coil of the transformer, and the receiving coil 16 functions as a secondary coil of the transformer.

Therefore, when the oscillation circuit of the charging section oscillates,
The parallel resonance circuit forming the oscillation circuit resonates at a predetermined frequency. At this time, the transmitting side coil 15 and the receiving side coil 16
Are electromagnetically coupled, the magnetic flux generated in the transmitting coil 15 is linked to the receiving coil 16, and a voltage is induced in the receiving coil 16.

The induced voltage causes the parallel resonant circuit of the charged portion to resonate, and the secondary battery 18 is charged by the output of the parallel resonant circuit. That is, at the time of charging, the parallel resonance circuit of the charging section and the parallel resonance circuit of the charged section resonate at the same time,
Charge the secondary battery. The operation of each unit will be described below.

(2): Description of Operation of Charging Unit In the charging unit, the power source plug 22 has a commercial frequency (50/60).
H _Z ) AC voltage is applied, the full-wave rectifier circuit 24 performs full-wave rectification, and the smoothing capacitor 25 performs smoothing to generate a smooth DC voltage at the terminals of the smoothing capacitor 25.

In the collector tuning type self-excited oscillating circuit including the oscillating capacitor 26, the resonance capacitor 29, the starting resistor 28, the switching transistor 27, and the transmitting coil 15, the oscillating operation is performed by the DC voltage as follows. To do.

First, when a current flows to the base of the switching transistor 27 through the starting resistor 28 and the feedback coil 30, a collector current of the switching transistor 27 flows and a current also flows to the transmission side coil 15. Then, this current gradually increases.

Therefore, a voltage is generated in the feedback coil 30, and the voltage generated in the feedback coil 30 causes a current to flow through the oscillation capacitor 26, the feedback coil 30, and the base of the switching transistor 27, so that switching is performed. The current of the collector of the use transistor 27 tends to further increase (increase in current due to positive feedback).

After that, when the voltage of the feedback coil 30 is reversed, the switching transistor 27 is turned off.
When the voltage of the feedback coil 30 is reversed after a lapse of time, a current again flows through the switching transistor 27, and the same operation as described above is performed.

In this way, the switching transistor 27 is turned on / off according to the polarity of the voltage of the feedback coil 30.
The off operation is repeated, but in this case, the parallel resonance circuit including the transmission side coil 15 and the resonance capacitor 29 is
It resonates at a predetermined frequency.

Therefore, the switching transistor 27
Is turned on and the collector current increases, the collector current of the switching transistor 27 becomes a sine wave current determined by the fixed frequency by the parallel resonant circuit. Therefore, the voltage generated in the feedback coil 30 also becomes a sine wave voltage of the above frequency, and the switching transistor 2
The collector voltage of 7 also becomes a sine wave voltage.

On the other hand, when the switching transistor 27 is off, the parallel resonant circuit is in a resonant state, so that the collector voltage of the switching transistor 27 becomes a continuous sine wave voltage.

As described above, the parallel resonance circuit resonates at a frequency determined by the inductance value of the transmitting coil 15 and the capacitance value of the resonance capacitor 29. Then, the oscillation circuit oscillates at the resonance frequency of the parallel resonance circuit.

(3) Description of Operation of Charged Part The charged part operates as follows during charging to charge the secondary battery. When the oscillating circuit of the charging unit is oscillating, the transmitting side coil 15 and the receiving side coil 16 are in a relationship of a transformer primary coil and a secondary coil, and are electromagnetically coupled to each other. Therefore, a voltage is induced in the receiving coil 16,
An electric current flows.

At this time, since the receiving coil 16 and the resonance capacitor 34 form a parallel resonance circuit, they resonate at a predetermined frequency determined by the receiving coil 16 and the resonance capacitor 34.

When this parallel resonant circuit enters a resonance state, a sine wave voltage is generated in the parallel resonant circuit. This voltage causes the smoothing capacitor 35 to pass through the rectifying diode 36.
A current flows through the smoothing capacitor 35, and a smoothed DC voltage is generated at the terminal of the smoothing capacitor 35.

The DC voltage generated at the terminals of the smoothing capacitor 35 causes the secondary battery 1 to pass through the constant current element 37.
A charging current flows through the battery 8, and the secondary battery 18 is charged. §4: Description of actual measurement example in non-contact type charger ... See FIGS. 5 and 6. FIG. 5 is an explanatory diagram of the measurement circuit, and FIG. 6 is an example of actual measurement data.
In order to confirm the effect of the charging characteristic by the charging section and the charged section of the above-mentioned example, the charging characteristic was measured by the measuring circuit shown in FIG. 5 and the actual measurement data shown in FIG.

(1): Description of measuring circuit and measuring method ... See FIG. 5 When measuring the characteristics of the charging part and the charged part, the electric shaver 12 is charged using the measuring circuit shown in FIG. The measurement was performed by turning on the power in a state where the electric shaver was placed on the electric shaver placing portion 20 of the unit stand 10 (see FIGS. 2 and 3).

As the measuring circuit, the circuit of the charging part and the charged part described in the above embodiment was used. In this case, the constant current element 37 provided in the charged part was removed, and as shown in FIG. The ammeter 38 and the voltmeter 39 were connected.

The current measured by the ammeter 38 was I ₀ (mA), and the voltage measured by the voltmeter was V ₀ (V). In this case, the current I ₀ is the charging current of the secondary battery 18, and the voltage V ₀ is the terminal voltage of the secondary battery.

The capacitance value of the resonance capacitor 29 is C
_P , the inductance value of the transmission side coil 15 is L _P , the inductance value of the reception side coil 16 is L _S , the capacitance value of the resonance capacitor 34 is C _S , the resonance frequency of the parallel resonance circuit of the charging unit is f ₁ , and during charging The gap length between the transmitting side coil 15 and the receiving side coil 16 in was set to L _g (see FIG. 3).

The constants at the time of measurement are C _P =
2200 pF, L _P = 4.6 mH, L _S = 16 μH, and the measured frequency f ₁ is f ₁ = 1 / √2πC _P L _P
= 250 KH _Z.

Further, the transmitting side coil 15 and the receiving side coil 1
The gap length L _{g of} 6 is 6.0 mm, the diameter of the transmitter coil 15 is 38 mm, and the thickness of the transmitter coil 15 is 3.9 m.
m, the diameter of the receiving side coil 16 was 26 mm, and the thickness of the receiving side coil 16 was 1.6 mm.

While the above constants are set and the capacitance value C _S is changed as a parameter, the charging current I is measured by the ammeter 38.
₀ is measured, and the voltmeter 39 measures the terminal voltage V _{0 of the} secondary battery 18.
Was measured. When the resonance frequency of the parallel resonance circuit of the part to be charged is f ₂ , f ₂ = 1 / √πL _S C _S.

(2): Description of Measurement and Description of Measured Data Example In the oscillation circuit of the charging section, the resonance frequency f ₁ = determined by the inductance value of the transmitting coil 15 and the capacitance value of the resonance capacitor 29. It oscillates at 1 / √2πC _P L _P. In the example, the resonance frequency f ₁ measured by selecting the constant as described above was f ₁ = 250 KH _Z as described above.

In this case, the frequency f _{1 is} applied to the transmitting coil 15.
AC current flows, and magnetic flux is generated in the vertical direction from the ferrite core. This magnetic flux interlinks with the receiving side coil 16 that constitutes the parallel resonance circuit of the charged portion, and induces a voltage in the receiving side coil 16. By this induced voltage, the receiving coil 1
The parallel resonance circuit composed of 6 and the resonance capacitor 34 resonates. The resonance frequency f ₂ at this time, varies with the capacitance value C _S, determined by _{f 2 = 1 / √πL S C} S.

Then, a DC voltage is generated at the terminal of the smoothing capacitor 35 by the voltage generated by the resonance operation of the parallel resonance circuit of the part to be charged, and the secondary battery 1 is generated by this DC voltage.
Charge 8 At this time, the ammeter 38 measured the charging current I ₀ at the time of charging, and the voltmeter 39 measured the terminal voltage V ₀ of the secondary battery to obtain the data shown in FIG.

In this measurement, the capacitance value C _S of the resonance capacitor 34 is C _S = 0 (μF) → 0.22 (μF) → 0.
33 (μF) → 0.43 (μF) → 0.53 (μF) →
The measurement was performed while changing it to 0.63 (μF).

In the actual measurement data shown in FIG. 6, the horizontal axis represents the charging current I ₀ (mA) and the vertical axis represents the terminal voltage V ₀ (V) of the secondary battery.
It is shown as. C _S = 0 (μF) corresponds to the case where the resonance capacitor 34 is not provided, and is the same state as that of the conventional example.

According to the data of FIG. 6, the capacitance value C _{S is set} to C _S
= 0 (μF) → 0.22 (μF) → 0.33 (μF) →
0.43 (μF) → 0.53 (μF) → 0.63 (μ
As F) increases, both the charging current I ₀ and the terminal voltage V _{0 of the} secondary battery increase, resulting in good charging characteristics.

Particularly, the capacitance value C _{S is set} to 0.53 (μF) →
When changed to 0.63 (μF), even if the charging current I ₀ increases, the terminal voltage V ₀ of the secondary battery is in a sufficiently high state, which is suitable for high-speed charging.

That is, the capacitance value C _S = 0.63 (μF)
Then, the charging current I ₀ and the terminal voltage V _{0 of the} secondary battery are maximum values, and the parallel resonant circuit output power Q = V ₀ × I
₀ (W) was the maximum.

The condition for f ₁ = f ₂ is f ₁ = 1
/ √2πC _P L _P = f ₂ = 1 / √πL _S C _S , and the calculation result is C _S = 0.634 (μF). In the above measurement, the capacitance value C _S is the above C _S = 0.634 (μF)
Charging current I ₀ at 0.63 (μF), which is slightly smaller than the value of
And the terminal voltage V _{0 of the} secondary battery was the maximum value, and the parallel resonant circuit output power Q = V ₀ × I ₀ (W) was the maximum. Further, within the range of C _S ≧ 0, 634 (μF), f ₁ ≧ f ₂
Then, the charging side became unable to oscillate.

This is because the transmitter coil 1 is used in the charging section.
5 and when the self-excited oscillation is continued by the positive feedback in the feedback coil 30, the current flowing in the parallel resonance circuit on the charged part side is delayed at a timing later than the time of one cycle in which the switching transistor 27 is switching. To reverse
This is because oscillation on the charging section side cannot be maintained.

As described above, as a result of the measurement, when C _S = 0, the terminal voltage of the secondary battery is extremely lowered, which is not suitable for rapid charging of the secondary battery. However, the value of C _S becomes large,
When C _S = 0.53 (μF) → 0.63 (μF), the charging current I ₀ and the terminal voltage V ₀ of the secondary battery become extremely large, and a large current is supplied to the secondary battery 18 in a short time. It becomes possible to flow and quick charge becomes possible.

§5: Description of Modified Circuit Example of Charging Part and Charged Part ... See FIG. 7 FIG. 7 is a diagram showing a modified circuit example of the charging part and charged part, and FIG. FIG. 2 is a circuit configuration diagram of a portion to be charged. FIG. The charging part and the circuit of the part to be charged are
It can also be implemented by modifying it as shown in FIG. Hereinafter, this modified circuit example will be described.

(1): Description of Charging Section This circuit example is an example in which a push-pull type oscillation circuit is used as the oscillation circuit of the charging section. Since the charging unit is configured to perform switching by the two switching transistors 41 and 42, the transmission side coil is also composed of two coils including the first transmission side coil 46 and the second transmission side coil 47. are doing. In addition, the starting resistance is two starting resistance 4
It is composed of 4, 45.

In this case, the first transmitting coil 46, the second
The transmission side coil 47 and the resonance capacitor 29 constitute a parallel resonance circuit. Also, the choke coil 4
3 is for making a constant current action of the current flowing through the circuit. The structure other than the above is the same as that of the above embodiment.

(2): Description of Charged Part In the charged part, a second receiving coil 49 and a second receiving coil 50 are provided according to the circuit of the charging part.
The receiver coil is used. In this case, the first reception side coil 49, the second reception side coil 50, and the resonance capacitor 34 form a parallel resonance circuit. The choke coil 51 is for smoothing. In addition,
Except for the above-mentioned constitution, it is the same as that of the above-mentioned embodiment.

(Other Embodiments) Although the embodiments have been described above, the present invention can be implemented as follows. (1): The oscillating circuit of the charging section is not limited to the circuit of the above embodiment, but can be applied to other similar oscillating circuits.

(2): The non-contact type charger having the charging part and the charged part can be used not only for the electric shaver but also for various devices such as a mobile phone and a cordless phone.

[0083]

As described above, the present invention has the following effects. (1): A parallel resonance circuit consisting of a coil and a capacitor is provided in the charging section, and a parallel resonance circuit consisting of a coil and a capacitor is also provided in the charging section, and at the time of charging, the parallel resonance circuit of the charging section and the parallel resonance of the charging section. The secondary battery is charged by causing the circuit and the circuit to resonate at the same time.

Therefore, the efficiency of power transmission from the charging section to the charged section can be improved and the secondary battery can be rapidly charged. (2): In particular, by selecting the capacitance value of the resonance capacitor that constitutes the parallel resonance circuit of the part to be charged, the terminal voltage of the secondary battery will not drop even if the charging current to the secondary battery increases. It is possible to do so.

Therefore, by selecting the capacitance value of the capacitor, it is possible to always perform high-speed charging in accordance with the characteristics of the secondary battery.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory diagram 1 of a non-contact type rechargeable electric shaver according to an embodiment.

FIG. 3 is an explanatory diagram 2 of a non-contact type rechargeable electric shaver according to an embodiment.

FIG. 4 is an explanatory diagram of a charging circuit according to an embodiment.

FIG. 5 is an explanatory diagram of a measurement circuit according to an example.

FIG. 6 is an example of actual measurement data in the example.

FIG. 7 is a diagram showing a modified circuit example of a charging unit and a charged unit in the embodiment.

FIG. 8 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 11 Charging Part Stand Housing 13 Electric Shaver Housing 15 Transmission Side Coil 16 Reception Side Coil 17 Electromagnetic Shielding Plate 18 Secondary Battery 25 Smoothing Capacitor 26 Oscillation Capacitor 27 Switching Transistor 28 Starting Resistor 29 Resonance Capacitor 30 Feedback Coil 34 Resonance Capacitor 35 Smoothing capacitor 36 Rectifier diode

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[Procedure amendment]

[Submission date] May 30, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0085

[Correction method] Change

[Correction content]

Therefore, by selecting the capacitance value of the capacitor, it is possible to always perform high-speed charging in accordance with the characteristics of the secondary battery. (3): When there is no electromagnetic shield, it occurs in the transmitting coil
The generated electromagnetic field reaches the secondary battery and swirls in the metal body of the secondary battery.
An electric current flows. As a result, the secondary battery heats up and the secondary battery
It may deteriorate. However, in the present invention,
Between the coil forming the parallel resonant circuit and the secondary battery,
Electromagnetic shielding to shield the electromagnetic field generated in the charging section
Since the plate is placed, it blocks the electromagnetic field generated in the transmitter coil.
It is possible to shield the secondary battery from heat generation.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location H01F 27/36 7522-5E H02J 17/00 B H05K 9/00 F // A46B 17/00 7361-3K

Claims (2)

[Claims] 1. A charging unit and a charged unit are separately configured, the charging unit includes an oscillation circuit including a parallel resonance circuit of a coil and a capacitor, and the charged unit has the oscillation circuit during charging. A non-contact charger including a coil for electromagnetically coupling with a coil of a circuit to induce a voltage, and a secondary battery that can be charged by the voltage induced in the coil, wherein a capacitor is provided in parallel with the coil of the part to be charged. A non-contact type charger characterized in that a parallel resonance circuit is configured by connecting the two. 2. An electromagnetic shielding plate for shielding an electromagnetic field generated in the charging section is arranged between the coil and the secondary battery forming the parallel resonant circuit in the charged section. The non-contact type charger according to claim 1.