JPH09130998A - Power supply unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a thinner power supply unit of non-contact type to be used for a compact, portable equipment. SOLUTION: This unit, made up of a primary coil 4a to which a current is supplied and an opposing secondary coil 8a mounted in a separate box from that of the primary coil 4a, transmits power from the primary coil 4a to the secondary coil 8a. In this unit, the primary coil 4a comprises an I-shaped core 1a and primary windings provided in its circumference, while the secondary coil 8a is made up of a flat, T-shaped core 5a and secondary windings 6a or a printed circuit board 11 provided in the circumference of the center projection of the T-shaped core 5a. This makes it possible to obtain a much undersized and efficient power supply unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes electromagnetic induction,
The present invention relates to a non-contact power supply device for transmitting electric power from an independent first coil to a second coil, and more particularly to a power supply device such as a cordless telephone or PHS that requires miniaturization.

[0002]

2. Description of the Related Art In a non-contact type power supply device, a primary side circuit and a secondary side circuit are mounted in a completely independent housing, and in order to efficiently transmit electric power, a primary coil and a secondary coil are required. Magnetic coupling becomes extremely important. As a means for improving this magnetic coupling, it is considered effective to use an E-shaped core for the secondary coil. In addition, it has been common to shorten the gap (distance) between the primary coil and the secondary coil or widen the facing area of the winding portions of both coils.

The related art is shown in FIGS. FIG.
Indicates that both the primary coil 4 and the secondary coil 8 have E
This is a configuration using the mold cores 1 and 5. The magnetic flux emitted from the primary coil 4 is transmitted to the E-shaped core 5 of the secondary coil 8 and the secondary winding 6.

Further, FIG. 4 shows a wide area in which the primary winding 2 and the secondary winding 6 face each other, and the transmissibility between the windings is improved.

FIG. 5 is an external view of the E-shaped core 5 used in the secondary coil 8 shown in FIGS.

[0006]

Since the magnetic circuit has an open magnetic circuit in the conventional structure as described above, the magnetic flux emitted from the primary coil 4 is emitted in multiple directions. Therefore, when the secondary coil 8 is the E-shaped core 5, only a partial magnetic flux in the core cross section can be picked up, and since there is a short circuit of the magnetic flux between the middle leg and the outer leg of the E-shaped core, the transmissibility is limited. there were.

Further, the one in which the area where the primary coil 4 and the secondary coil 8 face each other is widened has an extremely large shape on both the primary side and the secondary side including the housing, which is a serious drawback for downsizing of equipment. is there.

While it is desired to make the secondary coil 8 small and thin, it has been extremely difficult to make the conventional coils thinner.

Therefore, the present invention eliminates the above-mentioned conventional drawbacks, makes it possible to reduce the thickness of the secondary coil with a simple structure, and provides an efficient and highly reliable power supply device.

[0010]

In order to solve the above problems, the present invention provides a first coil supplied with a high frequency current,
In a non-contact type power supply device that opposes a second coil mounted in a housing different from the first coil, and that transmits power from the first coil to the second coil,
The surface where the first coil and the second coil face each other is flattened, and the first coil has a primary winding around an I-shaped core, and the second coil is a flat T-shaped core. A printed wiring board having a secondary winding or a coil pattern is provided around the protrusion of the T-shaped core, and the secondary coil can be downsized by making it thin, efficient, and reliable. Thus, it is possible to realize a non-contact type thin power supply device that is highly versatile.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention comprises: a first coil supplied with an electric current; and a second coil mounted in a housing different from the first coil. And a non-contact type power supply device for transmitting electric power from the first coil to the second coil, the first coil having a primary winding around an I-shaped core, and The second coil uses a flat T-shaped core and a printed wiring board having a secondary winding or a coil pattern around the protrusion of the T-shaped core. By using the flat T-shaped core, It is an efficient and thin contactless power supply device.

An embodiment of the present invention will be described below with reference to FIGS. (Embodiment 1) FIG. 1A is a configuration diagram of a secondary coil 8a. A flat T-shaped core is used as the secondary core 5a, and the secondary winding 6a is arranged around the protrusion of the T-shaped core to form the secondary coil 8a.

FIG. 1B is a sectional view of the primary coil 4a and the secondary coil 8a. The primary coil 4a supplied with the high frequency current emits a magnetic flux toward the secondary coil 8a. At this time, since the magnetic circuit is an open magnetic circuit, magnetic flux is emitted from the primary coil 4a in multiple directions. In order to increase the transmission efficiency, it is necessary to concentrate the magnetic flux emitted from the primary coil 4a and to collect more magnetic flux in the secondary coil 8a. However, the primary core 1a has an I-shaped core and the secondary coil 8a has a flat shape. Primary coil 4 using the T-shaped core 5a of
By concentrating the magnetic flux emitted from a and picking it up on the entire surface of the secondary core 5a, the transmissivity is extremely improved,
The secondary coil 8a can be made thinner.

Here, the shape of the flat core used as the secondary core 5a and having a T-shaped side cross section may be round, elliptical, square or polygonal on the upper surface.

(Embodiment 2) FIG. 2 shows another embodiment of the present invention in which the secondary coil is formed on the printed wiring board 11, and (a) shows the surface of the printed wiring board 11. b) shows the back side.

As shown in the figure, the coil patterns 13 are concentrically provided on the front and back of the substrate 12, and the front and back patterns 13 are connected to each other by through holes 14 in the inner portion. This makes it possible to receive the magnetic flux emitted from the primary coil 4 in the same manner as the generally used secondary winding 6 and further reduce the thickness of the secondary coil 8.

Here, the printed wiring board 11 may have a round shape, an elliptical shape, a square shape, or a polygonal shape corresponding to the shape of the secondary coil 5, and the substrate 1
2 may be a double-sided substrate, a single-sided substrate or a multi-layered substrate.

[0018]

As described above, according to the present invention, by providing the flat T-shaped core as the secondary core, a thin secondary coil can be realized with a simple structure, the device can be downsized, and the efficiency can be improved. It is possible to realize a highly reliable non-contact type power supply device.

Further, by using the T-shaped core, the core material of the outer foot portion of the E-shaped core can be reduced as compared with the E-shaped core of the conventional example. Is of great value.

[Brief description of the drawings]

FIG. 1A is a front view of a secondary coil that is a main part of a power supply device according to an embodiment of the present invention. FIG. 1B is a cross-sectional view illustrating the configurations of the same primary coil and the secondary coil.

2A is a top view of a printed wiring board, which is a main part of the other embodiment; FIG. 2B is a bottom view thereof; and FIG.

FIG. 3 is a configuration diagram of an E-type core, which is a main part of a conventional power supply device.

FIG. 4 is a configuration diagram of an E-shaped core which is a main part of the other power supply device.

FIG. 5 is a perspective view of an E-shaped core, which is the main part of the same.

[Explanation of symbols]

 1a primary core 2a primary winding 4a primary coil 5a secondary core 6a secondary winding 8a secondary coil 11 printed wiring board

Claims (1)

[Claims] 1. A first coil supplied with an electric current and a second coil mounted in a housing different from the first coil are opposed to each other, and the first coil is connected to the second coil. In the non-contact power supply device for transmitting electric power to the coil, the first coil is configured to have a primary winding around an I-shaped core, and the second coil uses a flat T-shaped core. A power supply device provided with a printed wiring board having a secondary winding or a coil pattern around a protrusion of a T-shaped core.