JPH09182304A - Non-contact charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the production of noise caused by the radiation of unnecessary electric waves to be interference to radios, TVs, etc., by transmitting power from a transmitting unit to a receiving unit by non-contact, and charging a secondary battery by the power received by the receiving unit. SOLUTION: When a transmitting unit 1 is operated with the transmitting unit 1 and a receiving unit 2 opposed to each other, a high-frequency electromagnetic field is generated from the transmitting unit 1, and power is transmitted. On the other hand, in the receiving unit 2, a voltage is induced in a receiving coil 26 by this high-frequency electromagnetic field. By the voltage generated in the receiving coil 26, a current is caused to flow in a capacitor 31 through diodes 29, 30 of a full-wave rectifying circuit, and a smoothed DC voltage is generated between the terminals of the capacitor 31. A constant current is outputted from a constant current circuit 32 by applying the terminal-to-terminal voltage of the capacitor 31 to the constant-current circuit 32, and a secondary battery 33 is charged by this constant current.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power source for household electric equipment such as an electric shaver (electric shaving device), a cordless telephone, a mobile telephone, an electric toothbrush, a laptop personal computer, and various other office automation equipment. The present invention relates to a contactless charger used as a power source. Particularly, the present invention comprises a transmission unit (charging unit) that transmits electric power and a receiving unit (charged unit) that receives the electric power transmitted from the transmitting unit, and the transmitting unit does not contact the receiving unit. The present invention relates to a non-contact type charging device that transmits electric power and charges a secondary battery with the electric power received in a receiving unit.

A non-contact type power transmission device, such as a portable telephone or an electric shaver, which needs charging as described above.
With the widespread use of devices using secondary batteries, their use is increasing for the purpose of preventing accidents such as contact failure of contact parts and electric shock.
The principle of non-contact type power transmission is that the transmitting side and the receiving side are magnetically coupled and electric power is transmitted in an electrically insulated state. Therefore, in simple terms, it is sufficient to convert the electric energy to be transmitted into high frequency power to drive the transmitting side coil, and use the voltage induced in the receiving side coil placed in the vicinity of the transmitting side coil.

However, since the range of use has expanded to household appliances and various office automation equipment, required characteristics are that it is small, that there is little unnecessary radio wave radiation that interferes with radios, televisions, etc., and power transmission. Be efficient,
It is possible to charge a large capacity secondary battery,
There has been a demand for the development of a non-contact type charger that satisfies such characteristics.

[0004]

2. Description of the Related Art A conventional example will be described below with reference to FIGS.
I will tell. §1: Description of Conventional Example 1 ... See FIG. 7 FIG. 7 is an explanatory diagram of Conventional Example 1. In Figure 7, Q is
Langista, D₁, D _TwoIs a diode and ZD is a zener
Diode, DB is diode bridge, L₁~ L_FourIs
Winding (coil), BT is a secondary battery, C₁, C_TwoIs a conde
Sensor, R₁, R _TwoIs resistance, A is charger, B is main body (charge
AC) indicates an AC power supply.

Conventionally, a charger and a main body (a portion to be charged) are provided, the charger is provided with an oscillation circuit, and the main body has a coil for electromagnetically coupling with the coil of the oscillation circuit to induce a voltage. Then, a device provided with a secondary battery that can be charged by the voltage induced in the coil has been known (see, for example, Japanese Utility Model Laid-Open No. 57-192737).

This device is a device for charging the secondary battery BT by magnetically coupling the main body B having the secondary battery BT inside and the main body B and the charger A. The charger A has an oscillation circuit that is magnetically coupled to the main body B, and a winding L ₃ that detects a coupling state with the main body B.
The oscillation of the oscillation circuit is intermittently stopped when the main body B and the charger A are not coupled.

§2: Description of Conventional Example 2 ... See FIG. 8 FIG. 8 is an explanatory diagram of Conventional Example 2. Conventionally, as a device for transmitting the electric power generated by the push-pull oscillation circuit to the load side, for example, a device (DC-DC converter) as illustrated is known (see Japanese Utility Model Laid-Open No. 4-101288). In FIG. 8, Q ₁ and Q ₂ are transistors and TR
Is a transformer, L ₁ is a primary winding of the transformer TR, L _f is a feedback winding of the transformer TR, L ₂ is a secondary winding of the transformer TR, R ₃ and R ₄ are resistors, C ₃ and C ₄ are capacitors. ,
T ₁ and T ₂ are input terminals, T ₃ and T ₄ are output terminals, and C
H ₁ and CH ₂ are choke coils, d ₁ is a diode, and E
Indicates the input voltage.

This device comprises a primary winding L ₁ of a transformer TR.
And a parallel resonance circuit composed of a condenser C3, two transistors Q ₁ and Q _2, and a feedback winding L of the transformer TR.
_{The f} and the resistors R ₃ and R _{4 form a} push-pull oscillator circuit. Then, a half-wave rectification circuit composed of a diode d ₁ is connected to the secondary side of the transformer TR, and a capacitor C ₄
The DC voltage smoothed by is taken out from the output terminals T ₃ and T ₄ .

In this device, two transistors Q ₁ ,
DC input on the primary side of the transformer TR with Q ₂ (input voltage:
By alternately turning on / off E), a push-pull oscillation operation is performed to induce a sinusoidal AC voltage in the parallel resonant circuit. Then, the induced AC voltage is converted into a predetermined voltage by the transformer TR, rectified by the diode d ₁ and then smoothed by the capacitor C ₄ via the choke coil CH ₂ , and the DC is output from the output terminals T ₃ , T _4. Taking out voltage.

[0010]

The above-mentioned prior art has the following problems. (1): In the conventional example 1, power is generated by an oscillation circuit (excitation circuit) using one transistor, and the power is transmitted to the main body side to charge the secondary battery. . Therefore, the collector current of the transistor does not have a sinusoidal waveform, but becomes an intermittent current. as a result,
Radiation noise from the charger increases.

(2): In Conventional Example 1, the output of the oscillation circuit is small because there is one transistor, and the charging current on the main body side is extremely small. Therefore, it can be applied only to trickle charging of a secondary battery or charging of an extremely small capacity secondary battery, and charging of a large capacity secondary battery is impossible.

(3): In Conventional Example 2, a push-pull type oscillation circuit is used as the oscillation circuit, and a sinusoidal oscillation output is obtained. However, the conventional example 2 is a DC using a transformer.
-This is an example of a DC converter, and it is not possible to separate the power transmission side and the power reception side.

(4): In Conventional Example 2, the secondary side of the transformer is a half-wave rectifier circuit, and no resonance circuit is provided. That is, since the coupling coefficient on the primary side and the secondary side of the transformer is as high as 0.9 or more, no resonance capacitor is connected to the secondary winding. Therefore, even if the secondary side output of the transformer is used for charging the secondary battery, efficient charging is impossible.

The present invention solves such a conventional problem as follows: There is less noise due to unnecessary radio wave radiation that interferes with radios, televisions, etc .: High power transmission efficiency, Larger capacity by increasing output current 2
The purpose of the present invention is to enable charging of a secondary battery and to realize a non-contact type charger satisfying the conditions such as.

[0015]

FIG. 1 is a diagram illustrating the principle of the present invention. The present invention is configured as follows to achieve the above object. As illustrated, the contactless charger includes a transmission unit 1 that transmits electric power and a reception unit 2 that receives the electric power transmitted from the transmission unit 1, and the transmission unit 1 does not contact the reception unit 2. The electric power is transmitted by using the electric power received by the receiving unit 2 to charge the secondary battery 33.

In this case, the transmission unit 1 and the reception unit 2 are configured separately, and the transmission unit 1 includes a parallel resonance circuit including a transmission coil 19 and a resonance capacitor 17, and 2
A push-pull oscillating circuit (push-pull type high-frequency power oscillating circuit) including individual transistors 15 and 16, a feedback coil 21, and resistors 13 and 14 for supplying a bias current is provided.

The receiving unit 2 has an intermediate tap b.
The receiving coil 26 and the resonance capacitor 2 having the GND side
A parallel resonance circuit with 8 is provided, and one terminal (cathode) is commonly connected to both terminals of the receiving coil 26.
The other electrodes (anodes) of the diodes 29 and 30 are connected to each other, and the smoothing capacitor 31 is connected between the commonly connected one electrode of the diodes 29 and 30 and the intermediate tap b of the receiving coil 26. Diode 29,
A full wave rectification circuit of 30 was constructed. Further, a constant current circuit 32 was connected to the output side of the smoothing capacitor 31, and a secondary battery 33 was connected to the output side of the constant current circuit 32.

(Operation) The operation of the present invention based on the above configuration will be described with reference to FIG. (1): Operation of the transmission unit 1 When the input power source (voltage: V _IN ) is applied to the transmission unit 1, the push-pull oscillator circuit starts operating. In the push-pull oscillating circuit, transistors 15 and 16 are connected via resistors 13 and 14 for supplying bias current by the voltage V _IN of the input power source.
A base current flows to the base of the, and one of the transistors turns on and the other transistor turns off.

For example, if the transistor 15 is turned on first, first, the input power source → the intermediate tap a → the transmission coil 19 → the collector of the transistor 15 → the emitter → GN.
The current starts to flow in the D route. Therefore, the feedback coil 2
When a voltage is induced in 1, positive feedback is applied so that the transistor 15 is turned on more and more, and eventually the transistor 15 is completely turned on.

On the other hand, the base of the transistor 16 is automatically reverse-biased by the voltage induced in the feedback coil 21, and when the transistor 15 is on, the transistor 16 is off. After that, the transistor 15 and the transistor 16 perform a push-pull operation, and alternately repeat on / off to continue self-excited oscillation.

In the above operation, the parallel resonance circuit including the transmission coil 19 and the capacitor 17 is in a parallel resonance state, and the parallel resonance circuit resonates at a frequency determined by the inductance value of the transmission coil 19 and the capacitance value of the capacitor 17. Then, in the transmission unit 1, the push-pull oscillating circuit oscillates high frequency at the resonance frequency of the parallel resonant circuit, and the transmission coil 19 transmits electric power by high frequency electromagnetic waves.

(2): Operation of the receiving unit 2 When the transmitting unit 1 is operated with the transmitting unit 1 and the receiving unit 2 facing each other, a high-frequency electromagnetic field is generated from the transmitting unit 1 as described above, and power is generated. Is transmitted. On the other hand, in the receiving unit 2, a voltage is induced in the receiving coil 26 by the high frequency electromagnetic field.

At this time, the receiving coil 26 and the capacitor 28
The parallel resonance circuit composed of is brought into a parallel resonance state at a predetermined frequency, and a resonance current flows through the receiving coil 26 and the capacitor 28. Then, the voltage generated in the receiving coil 26 causes a current to flow through the capacitor 31 through the diodes 29 and 30 of the full-wave rectifier circuit to generate a smoothed DC voltage between the terminals of the capacitor 31.

That is, when the point d, which is one terminal of the receiving coil 26, is +, a current flows through the route of the receiving coil 26 → point d → diode 29 → capacitor 31 → intermediate tap b and rectified by the diode 29. Current is capacitor 3
Flow to 1. When the point e, which is the other terminal of the receiving coil 26, is +, the receiving coil 26 → point e → diode 30
→ Capacitor 31 → Current flows through the route of intermediate tap b,
The current rectified by the diode 30 flows through the capacitor 31.

In this way, full-wave rectification is performed by the diodes 29 and 30, and a DC voltage smoothed by the capacitor 31 is generated. Then, by applying the voltage across the capacitor 31 to the constant current circuit 32, a constant current is output from the constant current circuit 32, and the secondary battery 33 is charged with this constant current.

With the above arrangement, the oscillation waveform of the transmission unit becomes sinusoidal and the reception voltage of the reception unit also becomes sinusoidal. Therefore, the generation of noise due to unnecessary radio wave radiation that interferes with radios, televisions, and the like is reduced, and power transmission efficiency can be improved. On the receiving side, full-wave rectification is performed to generate a smoothed DC voltage,
The secondary battery is being charged. Therefore, the output current on the receiving side becomes larger than that of the conventional example, and the large-capacity secondary battery can be charged.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. §1: Description of configuration of non-contact type charger ... See FIG. 2. FIG. 2 is a circuit configuration diagram. As shown in FIG. 2, the contactless charger includes a transmission unit (charging unit) 1 that transmits electric power.
And a receiving unit (charged portion) 2 that receives the electric power transmitted from the transmitting unit 1, the electric power is transmitted from the transmitting unit 1 to the receiving unit 2 in a non-contact manner, and the receiving unit 2 is provided. The secondary battery 33 is charged.

In this case, the transmitting unit 1 and the receiving unit 2 are configured separately, and the transmitting unit 1 is provided with a self-exciting type push-pull oscillation circuit (push-pull type high frequency power oscillation circuit), and this push-pull oscillation. The oscillation output (power) of the circuit is configured to be transmitted from the transmission coil 19. Further, the receiving unit 2 is provided with a receiving coil 26 for receiving the electric power transmitted from the transmitting unit 1,
By the electric power received by the receiving coil 26, the secondary battery 33
Configured to charge. Hereinafter, the configurations of the transmission unit 1 and the reception unit 2 will be described in detail.

(1): Structure of the transmitter unit 1 The push-pull oscillator circuit provided in the transmitter unit 1 has two NPs whose emitters are commonly connected to each other and are connected to GND.
N-type transistor (bipolar transistor) 1
5, 16, a transmission coil (main transmission winding) 19 wound around a core (for example, a ferrite core) 18, a feedback coil (feedback winding) 21, a bias current supply resistor 13,
14 and a resonance capacitor 17 connected in parallel with the transmission coil 19.

In this case, the transmitting coil 19 and the capacitor 1
Reference numeral 7 constitutes a parallel resonance circuit, and both terminals of the capacitor 19 are connected to the collectors of the transistors 15 and 16, respectively. A choke coil 12 for current limitation and a smoothing capacitor 11 are connected to the input side of the push-pull oscillator circuit.
The input power source 10 connected to the input terminals T ₁ and T ₂ is configured to be applied between the two terminals. in this case,
The input terminal T ₁ is the + side and T ₂ is the GND (ground side).

The input terminal T ₁ is connected to the choke coil 12
Is connected to the intermediate tap a of the transmission coil 19 via the choke coil 12 and the resistors 13 and 14 to the bases of the transistors 15 and 16 and the feedback coil 21.

(2): Configuration of the receiving unit 2 In the receiving unit 2, in order to receive the electric power transmitted from the transmitting unit 1, a core (for example, a ferrite core) is used.
A receiving coil 26 wound around 25 is provided, and a resonance capacitor 28 is connected in parallel to the receiving coil 26 to form a parallel resonant circuit. The anode of a rectifying diode 29 is connected to one terminal d of the receiving coil 26, the anode of a rectifying diode 30 is connected to the other terminal e, and the diode 2
The cathodes 9 and 30 are commonly connected at point f.

Further, a smoothing capacitor 31 is connected between the point f, which is a common connection point of the cathodes of the diodes 29 and 30, and the intermediate tap b of the receiving coil 26, and the output side of the capacitor 31 is connected. A constant current circuit 32 is connected to the output side of the constant current circuit 32, and a 2
The secondary battery 33 is connected.

§2: Description of circuit operation--see FIGS. 3 and 4 FIG. 3 is an explanatory diagram of circuit operation. Further, FIG. 4 is a waveform diagram of each part, where is the operating state (on / off state) of the transistor 15, is the emitter-collector voltage V _CE of the transistor 15, is the collector current I _C1 of the transistor 15, and is the transistor 15 of the transistor 15. The emitter-base voltage V _BE is the emitter-collector voltage V _CE of the transistor 16, and the resonance current I _R flowing through the capacitor 17,
Is the voltage V _S induced in the receiving coil 26, and is the phase angle φ.
Is shown. The input voltage of the transmission unit 1 is V _IN , the input current is I _IN , the output voltage of the reception unit 2 (constant current circuit 3
The output voltage of 2 is V _O and the output current is I _O.

(1): Operation of the transmitter unit When the input power source 10 (voltage: V _IN ) is applied, the input power source 1
A current flows through the capacitor 11 due to 0, and the capacitor 11
A smoothed DC voltage is generated. At this time, the DC voltage of the capacitor 11 is supplied to the push-pull oscillator circuit,
The push-pull oscillator circuit starts operating. In the push-pull oscillating circuit, the choke coil 12 and the bias current supply resistor 13 are supplied by the voltage of the capacitor 11.
A base current flows to the bases of the transistors 15 and 16 via 14, and one of the transistors turns on and the other transistor turns off.

For example, due to variations in the element constants h _FE (h _FE : DC current amplification factor) of the transistors 15 and 16,
It is assumed that the transistor 15 is turned on first. At this time, the transmission coil 19 is placed between the collectors of the transistors 15 and 16.
, And the feedback coil 21 is connected to the base, a magnetic flux is generated in the core 18 and passes from the input power source 10 through the intermediate tap a of the transmission coil 19 and the transmission coil 19.
The collector current I _C1 begins to flow in the collector of the transistor 15.

That is, the input power source 10 → choke coil 12 → intermediate tap a → transmission coil 19 → transistor 1
An electric current starts to flow in the path of collector → emitter → GND of 5. Therefore, when voltage is induced in the feedback coil 21, positive feedback is applied so that the transistor 15 is turned on more and more, and eventually the transistor 15 is completely turned on. On the other hand, the base of the transistor 16 is automatically reverse-biased by the voltage induced in the feedback coil 21, and when the transistor 15 is on, the transistor 16 is off.

After the transistor 15 is positively biased and turned on for a half cycle as described above, 18
When the 0 ° phase advances, the base of the transistor 15 is reverse biased and turned off. Conversely, transistor 16
The base of the is biased positive and turns on.
At this time, magnetic flux is generated in the core 18 and passes from the input power source 10 through the intermediate tap a of the transmission coil 19 and the transmission coil 19.
The collector current I _C2 (I _C2
≈I _C1 ) begins to flow.

That is, the input power source 10 → choke coil 12 → intermediate tap a → transmission coil 19 → transistor 1
Current starts to flow in the route of 6 collector → emitter → GND. Therefore, when voltage is induced in the feedback coil 21, positive feedback is applied so that the transistor 16 is turned on more and more, and eventually the transistor 16 is completely turned on.

On the other hand, the base of the transistor 15 is automatically reverse biased by the voltage induced in the feedback coil 21, and when the transistor 16 is on, the transistor 15 is off. Thereafter, the transistor 15 and the transistor 16 perform a push-pull operation, and alternately repeat on / off to continue self-excited oscillation.

In the above operation, the parallel resonant circuit formed of the transmitting coil 19 and the capacitor 17 is in a parallel resonant state, and this parallel resonant circuit resonates at a frequency determined by the inductance value of the transmitting coil 19 and the capacitance value of the capacitor 17. Then, in the transmission unit 1, the push-pull oscillation circuit oscillates high frequency at the resonance frequency of the parallel resonance circuit, and the transmission coil 19 transmits electric power by high frequency electromagnetic waves.

In the above operation, the transistors 15 and 1
The emitter-collector voltage V _CE of 6 is approximately 0 when the transistor is in the ON state as shown in FIG.
In the off state, the voltage waveform has a sinusoidal increase. The collector current I _C1 of the transistor 15 becomes a large current in the ON state and hardly flows in the OFF state. The collector current I _C2 of the transistor 16 is a similar current.

The emitter-base voltage V _BE of the transistor 15 is a substantially constant forward voltage when the transistor 15 is in the ON state, and is a reverse sinusoidal voltage when the transistor 15 is in the OFF state. Become. The resonance current I _R flowing through the capacitor 17 is a current advanced in phase by approximately 180 ° with respect to the collector current I _C1 , as indicated by.

(2): Operation of the receiving unit When the transmitting unit 1 is operated with the transmitting unit 1 and the receiving unit 2 facing each other, a high-frequency electromagnetic field is generated from the transmitting unit 1 and the power The transmission is done. On the other hand, in the receiving unit 2, the voltage V _S is induced in the receiving coil 26 by the high frequency electromagnetic field.

At this time, the parallel resonant circuit composed of the receiving coil 26 and the capacitor 28 is brought into a parallel resonant state at a predetermined frequency, and a resonant current flows through the receiving coil 26 and the capacitor 28. In this way, when the parallel resonance circuit is in a resonance state, a substantially sinusoidal waveform having the same phase as the resonance current I _R flowing through the capacitor 17 of the parallel resonance circuit on the transmission unit 1 side is formed between both terminals of the receiving coil 26. A voltage V _S is generated.

Then, the voltage V _S generated in the receiving coil 26 causes a current to flow through the capacitors 31 through the diodes 29 and 30 to generate a smoothed DC voltage between the terminals of the capacitor 31. That is, when the point d, which is one terminal of the receiving coil 26, is +, the receiving coil 26 → d point →
A current flows through the route of diode 29 → capacitor 31 → intermediate tap b, and the current rectified by the diode 29 flows into the capacitor 31.

When the point e which is the other terminal of the receiving coil 26 is +, the receiving coil 26 → point e → diode 30
→ Capacitor 31 → Current flows through the route of intermediate tap b,
The current rectified by the diode 30 flows through the capacitor 31. In this way, full-wave rectification is performed by the diodes 29 and 30, and a DC voltage smoothed by the capacitor 31 is generated.

By applying the voltage across the capacitor 31 to the constant current circuit 32, the constant current circuit 3
A constant current is output from 2, and the secondary battery 33 is charged with this constant current. In the above operation, the voltage V _S generated in the receiving coil 26 is, as shown in FIG.
The voltage is substantially in phase with the resonance current I _R flowing through the resonance capacitor 17 of FIG.

§3: Description of Mounting Example of Transmitting Unit and Receiving Unit--See FIG. 5 FIG. 5 shows an example of mounting the transmitting unit and the receiving unit.
The transmitter unit 1 has a printed circuit board 4 as shown in FIG.
A transmission coil 19 wound around a core (ferrite core) 18 and a feedback coil 21 are mounted on the circuit board 1, a circuit portion 42 other than the coils is mounted, and the printed board 41 is housed in a case 40. Is.

Further, the receiving unit 2 is provided with a case 35 as shown in FIG.
The receiving coil 2 wound around the core (ferrite core) 25
6 and the printed circuit board 36 on which the other circuit portion 37 except the receiving coil is mounted.

When charging the secondary battery 33 using the transmitting unit 1 and the receiving unit 2, the state shown in FIG. That is, with the input unit 10 connected to the transmission unit 1 and the secondary battery connected to the reception unit 2,
The receiving unit 2 is placed on the transmitting unit 1. Then, the transmission coil 19 and the reception coil 26 are arranged so as to face each other. The positioning of the transmission unit 1 and the reception unit 2 is realized by providing a positioning member on a part of the transmission unit 1 and the reception unit 2, for example.

In this state, high frequency power is transmitted from the transmission unit 1 to the reception unit 2, and this power is received by the reception unit 2. Then, the receiving unit 2 generates a direct current voltage based on the received electric power and further makes it a constant current to charge the secondary battery 33.

§4: Description of characteristic chart--see FIG. 6 FIG. 6 is a characteristic chart. In the characteristic diagram of FIG. 6, the vertical axis represents the output voltage V _O (V) of the constant current circuit 32, and the horizontal axis represents the output current I _O (mA) of the constant current circuit 32 of the receiving unit 2.
For comparison, the characteristics of the conventional example 1 are also shown and shown. In this case, those shown in the figure are the characteristics of the present embodiment, and those shown in the figure are the characteristics of the conventional example 1.

As is clear from this characteristic diagram, the characteristic of the conventional example 1 shown in (1) has a low output voltage V _O and can be used only for trickle charging of a secondary battery or charging of an extremely small capacity secondary battery. . However, in the device of the present embodiment shown in (3), since the receiving unit 2 performs full-wave rectification, the output voltage V _O is extremely large and the output current I _O is also large. Therefore, even a secondary battery having a large capacity can be sufficiently charged.

The power transmission efficiency η is η = (input voltage × input current) / (output voltage × output current) = V _IN × I _IN /
V _O × I _O (%). Therefore, if V _IN × I _IN is constant, the non-contact type charger in the present embodiment having a large V _O × I _O also has a higher power transmission efficiency η compared to Conventional Example 1, that is, high efficiency. It is clear that charging can be done.

(Other Embodiments) Although the embodiments have been described above, the present invention can be implemented as follows.

(1): The transistor provided in the transmission unit is not limited to a bipolar type transistor, but a field effect type transistor (MOS-FET or the like) can be similarly applied.

(2): The push-pull oscillator circuit of the transmission unit can be applied to other similar push-pull oscillator circuits.

[0059]

As described above, the present invention has the following effects. (1): The oscillation waveform of the transmission unit is sinusoidal, and the reception voltage of the reception unit is also sinusoidal. Therefore, the generation of noise due to unnecessary radio wave radiation that interferes with radios, televisions, and the like is reduced, and power transmission efficiency can be improved.

(2): In the receiving unit, a smoothed DC voltage is generated by performing full-wave rectification, and the secondary battery is charged by this DC voltage. Therefore, the output current on the receiving side becomes larger than that of the conventional example, and the large capacity 2
It is also possible to charge the secondary battery or quickly charge the secondary battery.

(3): Since the output voltage and the output current on the receiving unit side are increased, the power transmission efficiency is increased compared to the conventional example, and highly efficient charging can be performed.

[Brief description of the drawings]

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

FIG. 2 is a circuit configuration diagram in the embodiment.

FIG. 3 is an explanatory diagram of circuit operation in the embodiment.

FIG. 4 is a waveform chart of each part in the embodiment.

FIG. 5 is an implementation example of a transmission unit and a reception unit in the embodiment.

FIG. 6 is a characteristic diagram in the embodiment.

FIG. 7 is an explanatory diagram of Conventional Example 1.

FIG. 8 is an explanatory diagram of Conventional Example 2.

[Explanation of symbols]

 10 Input Power Source 11 Capacitor 12 Choke Coil 13, 14 Resistor 15, 16 Transistor 18 Core 19 Transmitting Coil (Main Transmission Winding) 21 Feedback Coil (Feedback Winding) 26 Reception Coil 17, 28 Capacitor (Resonance) 29, 30 Diode 31 Capacitor (for smoothing) 32 Constant current circuit 33 Secondary battery

Claims (1)

[Claims] 1. A transmitting unit for transmitting electric power and a receiving unit for receiving the electric power transmitted from the transmitting unit, wherein electric power is transmitted from the transmitting unit to the receiving unit in a non-contact manner, and inside the receiving unit. In the non-contact type charging device for charging the secondary battery with the electric power received in, the transmitting unit and the receiving unit are configured separately.
The transmission unit is provided with a push-pull oscillation circuit including a parallel resonance circuit of a transmission coil and a resonance capacitor, and the reception unit is provided with a parallel resonance circuit of the reception coil and the resonance capacitor whose center tap is the GND side. And the other electrodes of the two diodes, one electrode of which is commonly connected, are connected to both terminals of the receiving coil, respectively, and one electrode of the two diodes that are commonly connected and the intermediate tap of the receiving coil are connected. Connect a smoothing capacitor,
A non-contact type charger comprising a full-wave rectification circuit formed of the diode.