JPH09121481A - Non-contact charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of power transmission in a non-contact charger and reduce the cost of the manufacture thereof by opening a first coil on the side opposite to a third coil and a third coil on the side opposite to the first coil, and winding a second coil on a plane perpendicular to magnetic flux generated from the first coil. SOLUTION: A first coil 2 is wound around a spool 3a positioned around a projected core 1 with its side opposite to a third coil 6 open. The third coil 6 is wound around a spool 3a with its side opposite to the first coil 2 open. A second coil is wound on a plane perpendicular to magnetic flux generated from the first coil 2. The coil portion of a charger consists of a charging section obtained by winding the first coil 2, a coil for transmission, around a terminal block 3 containing the spool 3a without a brim and placing the obtained assembly in an enclosure 8a; and a charged section obtained by winding the third coil, a receiving coil 6, around a terminal block 5 containing the spool without a brim and placing the obtained assembly in an enclosure 8b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rechargeable battery used as a power source for cordless telephones, portable devices, etc., which is contactlessly supplied with electric power from a charging part to a charged part by means of an electromagnetic dielectric effect. The present invention relates to a charger that uses an electromagnetic induction coil for electric transmission, and relates to an electromagnetic induction device incorporated in a cordless telephone, a portable device, or the like.

[0002]

2. Description of the Related Art When a non-contact type charger using electromagnetic induction is oscillated with a substantially sine wave and a resonant circuit is used on the charged side to resonate in the vicinity of an excitation frequency, the charged portion is charged depending on the presence or absence of the charged portion. Since the excitation energy can be changed, a highly efficient charging device can be obtained.

Conventionally, in a self-excited oscillation circuit used for power transmission, in order to directly excite a commercial power source, it is necessary to increase the inductance of a primary coil, which makes it difficult to oscillate at a high frequency, and the load side. Because the frequency changes depending on the amount of power to the charger, the noise generated from the oscillation circuit may have an adverse effect on the device equipped with the charger, or even on the electromagnetic induction generating coil of the non-contact charger. Since it is difficult to provide a protection function against abnormalities such as when a coin is placed, it is not practical and a separately excited oscillation circuit has been adopted.

However, the separately-excited oscillation circuit requires a special circuit for controlling and driving the switching element, which not only complicates the circuit, but also deteriorates efficiency due to power consumption of the control circuit. Furthermore, since the number of parts increases, the manufacturing cost increases. Therefore, a charger having a simple circuit configuration and low power consumption has been desired.

Circuit systems satisfying such requirements are disclosed in Japanese Patent Laid-Open Nos. 4-295284 and 6-225528.

FIG. 6 shows a circuit diagram for non-contact power feeding by a class C self-exciting converter which is one of them.

The charging unit 9 has a resonance capacitor (C1) connected in parallel with the power transmission coil (T1), and performs a switching operation of the direct current input from the positive electrode 9a and the negative electrode 9b of the direct current input terminal by the field effect transistor (Q1). Let An oscillation feedback coil (T2) is arranged in order to continuously perform a switching operation to continue oscillation, and a bias capacitor (C2) is connected to one end of the coil. In order to improve the power efficiency, it is necessary to surely perform the class C operation, and therefore the resistor (R2) and the diode (D1) are connected.

The charged part 10 is constituted by connecting a diode (D11), a third capacitor (C11) and a fourth capacitor (C12) to a power receiving coil (T3).

Since the charger constituted by the charging part and the charged part is a self-excited oscillation type, it has a small number of parts, the circuit configuration is simple, and the product cost is lower than the conventional separately excited type. it can.

FIG. 7 shows the structure of the coil portion in the conventional charger represented by the non-contact charger using the class C self-exciting converter described above.

The charging unit includes a coil bobbin 12, a power transmission coil (T1) 13 and an oscillation feedback coil (T2) 14.
Winding and insert core 1. After that, make them housing 1
Put in 5 and configure.

The part to be charged is constructed by winding a power receiving coil (T3) 18 around a coil bobbin 17 and inserting it into the housing 16. By bringing the charging unit and the to-be-charged unit configured as described above close to each other, electric power is transmitted to form a charging circuit.

[0013]

The coil bobbin 12 of the charging section has a collar 12a for winding and holding the power transmission coil (T1) 13 and the oscillation feedback coil (T2) 14. Further, the coil bobbin 17 of the portion to be charged has a collar 17a for winding and holding the power receiving coil (T3) 18.

In the operation of the charger for transmitting electric power, it is necessary to increase the electric power transmission efficiency in order to suppress heat generation and charge the rechargeable battery with a loss as low as possible. The power transmission efficiency has a characteristic that it increases as the distance between the charging part and the charged part (hereinafter abbreviated as GAP) decreases.

However, the collar and housing of the coil bobbin need to have a certain strength or more in order to satisfy their respective functions, and for that purpose, a certain thickness or more is required. Therefore, GAP cannot be made smaller than the sum of the thicknesses of the housing and the coil bobbin, and it has been difficult to improve the power transmission efficiency.

Further, since the self-excited oscillator circuit requires the oscillation feedback coil (T2) in addition to the power transmission coil (T1), a step of winding the oscillation feedback coil (T2) is required, resulting in a manufacturing cost. To rise.

Therefore, an object of the present invention is to provide a non-contact charger with improved power transmission efficiency and low manufacturing cost.

[0018]

In order to achieve the above object, the invention according to claim 1 separates a charging part and a charged part, and the charging part oscillates with a first coil for power transmission. In a non-contact charger including a high frequency oscillation circuit having a second coil which is a feedback coil for use, and a portion to be charged including a third coil for receiving electric power, the first coil has a convex shape. The second coil is wound around a surface of the core that is perpendicular to the magnetic flux generated by the first coil, and is wound around a surface of the core facing the third coil. The non-contact charger is characterized in that the third coil is wound through a winding frame whose surface facing the first coil is open.

Furthermore, the invention according to claim 2 is the same as claim 1.
In the invention described above, the above-mentioned object can be achieved more reliably by using the second coil as a printed coil printed in a foil shape.

In order to achieve the purpose more reliably,
According to a third aspect of the present invention, in the invention according to the second aspect, the print coil printed in the foil shape is on the opposite side of the convex core from the first coil around the convex core. And a non-contact charger that is arranged at substantially the same position as the central axis of the first coil.

[0021]

With the above structure, the first coil for power transmission is wound around the convex core around the convex core and the winding frame whose surface facing the third coil is open. The coil can be arranged so that the coil portion of the first coil directly contacts the housing, and the distance from the third coil for receiving the electric power can be reduced. Further, since it is possible to wind the first coil as a bobbinless coil using a wire having a self-bonding action such as a cement wire and insert it into the winding frame, it is possible to reduce the number of steps.

Further, since the third coil is wound through the winding frame whose direction opposite to the first coil is open, the distance between the charging part and the charged part is further reduced, and power transmission is performed. Efficiency is improved.

If the second coil, which is a feedback coil for oscillation, is arranged on a plane perpendicular to the magnetic flux generated by the first coil, electromagnetic coupling with the first coil is good, and feedback for oscillation is good. Therefore, the oscillation can be easily continued. Here, in general, the feedback voltage may be relatively small, so that it is possible to reduce the number of turns of the second coil,
It is also possible to use a spiral coil printed on a printed circuit board or a flexible circuit board.

Therefore, it is possible to manufacture a large number of windings by using the printing technique and in which the variation in the inductance generated by the winding method is small, and as described above, the second coil is the first coil. Since it is possible to sufficiently perform its function by arranging it on the surface perpendicular to the magnetic flux generated by the coil, the second coil printed on the surface perpendicular to the magnetic flux must be It is also possible to insert the core in one coil and then place the second coil outside the core.

With the above-mentioned structure, a non-contact type charger having high power conversion efficiency and a small number of steps can be realized.

[0026]

EXAMPLES Next, the present invention will be described in detail with reference to examples.

FIG. 1 is a perspective view showing an embodiment of the non-contact charger according to the present invention in which the housings of the charging part and the charged part are omitted. The charging unit is a terminal block 3 having a collar 3a without a collar.
A bobbinless coil 2 made of cement wire or the like is inserted in and the terminals of the coil are connected to a substrate 4 which constitutes an oscillation circuit.

The part to be charged is a terminal block 5 having a collar without a collar.
The bobbinless coil 6 as described above is inserted in the winding frame portion of the above.

FIG. 2 shows a structural diagram of an embodiment of the charging unit of the contactless charger according to the present invention.

As shown in FIG. 2A, the core 1 is inserted into the terminal block 3 having the first coil wound around the winding frame 3a and fixed with an adhesive or the like to form an oscillation circuit. The attached substrate 4 is attached. As shown in FIG. 2B, the substrate 4 has a second coil 7 printed on the front surface 4a so as to form a spiral shape, and an oscillation circuit is formed on the back surface 4b.

Since the substrate 4 is arranged so as to be perpendicular to the magnetic flux generated from the core as shown in FIG.
The coil 7 is also arranged to be perpendicular to the magnetic flux.

Since the substrate can be attached after inserting the core 1 into the terminal block 3, the number of steps can be greatly reduced.

FIG. 3 shows a sectional view of the coil portion of the charger according to the present invention.

A charging section in which the first coil 2 which is a transmission coil is wound around the terminal block 3 having the winding frame 3a having no collar and is placed in the housing 8a, and the terminal block 5 having the winding frame having no collar. The coil portion is composed of the portion to be charged in which the third coil 6 which is the power receiving coil is wound and is placed in the housing 8b.

The GAPs of the charged part and the charged part are housings 8a, 8
It is configured only by the thickness of b, and the power conversion efficiency is greatly improved.

The conversion efficiency of the conventional non-contact charger wound around a bobbin with a collar and the non-contact charger according to the present invention is shown in FIG.
It becomes a graph like. It can be seen that the contactless charger according to the present invention has an efficiency improvement of about 5 to 10% as compared with the conventional contactless charger.

Although the self-excited non-contact charger according to the present invention can be achieved by performing the class C operation as described above, the circuit as shown in FIG. 6, that is, the charging section, has the positive electrode 9a of the DC input terminal on one side. The first coil (T1) for electric power transmission, which is connected to the terminal of
And a first for parallel resonance connected in parallel with the first coil.
Of the field effect transistor (Q1), the source of the field effect transistor (Q1) is connected to the negative electrode 9b of the DC input terminal, and the gate of the field effect transistor (Q1) is connected to one terminal of the other side. A first resistor (R1) connected to the positive electrode of the DC input terminal and a first resistor connected in series with the first resistor, and the other terminal connected to the negative electrode of the DC input terminal. A second coil (T2) connected to the connection point of the second capacitor (C2), a second resistor (R2) connected in series between the gate and source of the field effect transistor (Q1), and a third Connection point of the resistor (R3), the first resistor (R1), and the second capacitor (C2)
The non-contact charger composed of the high frequency self-excited oscillation circuit composed of the diode (D1) connected between the connection points can more effectively form the resonance type class C self-excited oscillation circuit.

[0038]

As described above, the present invention improves the power conversion efficiency by reducing the distance between the charging part and the charged part by using the terminal block.

Further, the feedback coil of the self-excited oscillation circuit can be easily manufactured, and the contactless charger can be easily manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a non-contact charger according to the present invention.

FIG. 2 is a structural diagram of a non-contact charger according to the present invention.

FIG. 3 is a sectional view of a non-contact charger according to the present invention.

FIG. 4 Comparison data of power conversion efficiency

FIG. 5 is a circuit diagram showing an embodiment of a non-contact charger according to the present invention.

FIG. 6 is a circuit diagram showing an example of a conventional non-contact charger.

FIG. 7 is a sectional view showing an example of a conventional non-contact charger.

[Explanation of symbols]

 1 core 2 1st coil 3 terminal block of charging part 4 substrate 5 terminal block of charged part 6 third coil 7 second coil 8 housing 9 charging part 10 charged part 11 rechargeable battery 12 charging side coil bobbin 13 Power Transmission Coil 14 Oscillation Feedback Coil 15 Charging Side Housing 16 Charging Side Housing 17 Charging Side Coil Bobbin 18 Power Receiving Coil

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H04M 1/02 H01F 23/00 B

Claims (3)

[Claims] 1. A charging part and a charged part are separated from each other, and the charging part is composed of a high frequency oscillation circuit having a first coil for power transmission and a second coil which is a feedback winding for oscillation. In the non-contact charger in which the charging unit is composed of a third coil for receiving electric power, the first coil is wound around a convex core whose surface facing the third coil is open. The second coil is wound on a surface perpendicular to the magnetic flux generated by the first coil, and the third coil is wound such that the surface facing the first coil is open. A non-contact charger that is lined. 2. The non-contact charger according to claim 1, wherein the second coil is a printed coil printed in a foil shape. 3. The printed coil printed on the foil,
The first coil around the convex core and the opposite side of the convex core sandwiching the convex core are arranged at substantially the same position as the central axis of the first coil. Non-contact charger.