JPH0748428B2 - Common mode choke coil - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a common mode choke coil for preventing noise of a power supply, for example.

2. Description of the Related Art Generally, in a common mode choke coil, two coils 40 and 41 as shown in FIG. 5 mutually generate magnetic flux by line current so that magnetic flux generated by line current does not saturate the ring-shaped closed magnetic circuit core 39. In the closed magnetic circuit magnetic core used in the related art, most of them are ring-shaped closed magnetic circuit magnetic cores 39 as shown in FIG. 5, and others are shown in FIG. A square closed magnetic circuit core 42 such as the mouth character and the day character as shown is used.
First coil 4 using bobbins 45, 46 in the rectangular closed magnetic circuit core 42
3, The second coil 44 is wound.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above-mentioned configuration, when the ring-shaped closed magnetic circuit magnetic core 39 like the conventional one is used, the circumference of the magnetic core is different from that of the magnetic core inner diameter, so that the number of turns of the coils 40, 41 is increased. And the winding cross on the inner diameter side of the magnetic core, which makes the winding work extremely difficult. Further, when the number of turns is increased and the multi-layer winding is performed, the potential difference increases, the distributed capacitance increases, and the high frequency characteristic of the attenuation amount of the common mode noise, which is its original function, is deteriorated. Therefore, as shown in FIG. 6, when the rectangular closed magnetic circuit magnetic core 42 is used, a linear portion is formed in the magnetic path. Therefore, the winding can be facilitated by using the bobbins 45 and 46, but the magnetic path is square or long. Since it is a quadrangle, a right-angled portion is formed on the magnetic path, and leakage magnetic flux is concentrated on the right-angled portion, and if there are inductance components in the periphery, they may be affected. Further, when performing the divided winding, it is difficult to divide without using the bobbins 45 and 46, and if it is attempted to surely divide without using the bobbin, even if the four sides are properly used, only about three divisions can be made.

In view of the above problems, the present invention facilitates winding work, reduces distributed capacitance and improves high frequency characteristics, and can reliably perform multi-division winding without using a bobbin, and has a relatively uniform leakage flux distribution. The present invention provides a common mode choke coil that is easily adapted.

Means for Solving the Problems In order to solve the above problems, the present invention uses a polygonal closed magnetic circuit magnetic core having at least a pentagon or more and is configured by dividing and concentrating windings on each linear portion of the magnetic path. It is a thing.

Action According to the above means, the winding work is facilitated by forming a straight line portion in the magnetic path, and a certain number of turns is concentrated on each straight line portion of the magnetic path to divide the total number of turns, so that the potential difference is By reducing the size, the distributed capacitance can be reduced and the high frequency characteristics can be improved. Moreover, even if the bobbin is not used, if there are as many linear portions of the magnetic path as desired to be divided, not only can the divided winding be performed reliably, but also the distribution of the magnetic flux leaking from that corner will be dispersive. Also, the adverse effect is less likely to occur even when the inductance component is arranged in the periphery. Also,
The degree of coupling can be easily changed by combining the windings divided on each straight line portion of the magnetic path, so that the leakage flux can be changed to adjust the saturation characteristics of the magnetic core and the normal mode noise attenuation effect. It is also possible to adjust.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a top view showing an embodiment of a common mode choke coil according to the present invention. The divided windings 4, 5, 6 and 7 of the first coil 2 are connected to the straight line portion 12 of the magnetic path of the octagonal closed magnetic circuit core 1.
Apply to 13,14,15. Next, the split windings 8, 9,
10 and 11 are applied to the linear portions 16, 17, 18, and 19 of the magnetic path of the magnetic core 1.
However, the winding directions of the two coils 2 and 3 are such that the magnetic fluxes generated by the line currents cancel each other.

FIG. 2 is a diagram showing the amount of attenuation of the common mode choke coil with respect to common mode noise. In the figure, the curve A is the common mode choke coil of FIG. 1 according to the present invention, and the curve C is the 1 coil 10
The same inductance value at KHz is formed by the conventional ring-shaped closed magnetic circuit magnetic core shown in FIG. 5, and the curve B shows the same inductance value at 10 KHz of the coil shown in FIG. It is composed of a quadrangular closed magnetic circuit core. However, all three types of closed magnetic circuit cores are made of the same material and have the same weight. Further, when the leakage magnetic flux at 10 KHz is measured, it is found that the common mode choke coil of the present invention has 62 μH and the conventional ring-shaped closed magnetic circuit magnetic core is used for the coil inductance value of 5 mH.
43μH, 120μ using a conventional rectangular closed magnetic circuit core
It was H. In this embodiment, the regular octagonal closed magnetic circuit core 1 is used, but the same effect can be obtained by using a pentagonal or more polygonal closed magnetic circuit magnetic core. It may be determined based on the leakage distribution of

Next, an embodiment will be described with reference to the drawings, in which the degree of coupling is changed by combining the respective windings wound on the linear portion of the magnetic path of the closed magnetic circuit core according to the present invention.

FIG. 3 is a top view showing another embodiment of the common mode choke coil according to the present invention. Octagonal closed magnetic circuit core 1
The windings 4 to 11 are applied to the straight line portions 12 to 19 of the magnetic path. Next, four of these eight windings are arbitrarily selected, and they are connected in the same winding direction to form the first coil 2. Then, the remaining four windings are connected in the same winding direction to form the second coil 3. However, the winding directions of the two coils 2 and 3 are such that the magnetic fluxes generated by the line currents cancel each other. In FIG. 3, the windings 4, 6, 9 and 11 are used as the first coil 2, and the windings 5, 7, 8 and 10 are used as the second coil 3. According to the connection shown in FIG. 3, the degree of coupling was increased, and the leakage magnetic flux at 10 KHz was 20 μH with respect to the coil inductance value of 5 mH. By changing the combination of windings, the leakage flux of the common mode choke coil shown in FIG. 3 could be set to an arbitrary value of 20 to 62 μH.

FIG. 4 is a diagram showing the attenuation of the common mode choke coil of the embodiment of the present invention with respect to normal mode noise. In the figure, the curve D shows a leakage flux of 20 μH, and the curve E shows a leakage flux of 40 μH, F Curve is due to a leakage flux of 62 μH.

EFFECTS OF THE INVENTION As described in detail above, the common mode choke coil according to the present invention facilitates winding work by forming a straight line portion in the magnetic path, and concentrates a certain number of turns on each straight line portion of the magnetic path. Since the total number of turns is divided by winding in order to reduce the distributed capacitance, it is very effective in reducing the amount of common mode noise in the high frequency range while obtaining the same inductance as the conventional configuration. . Moreover, even if the bobbin is not used, if there are as many linear portions of the magnetic path as desired to be divided, not only can the divided winding be performed reliably, but also the angle is obtuse and the distribution of the magnetic flux leaking from that angle becomes dispersive. Also, the adverse effect is less likely to occur even when the peripheral inductance components are arranged.

In addition, the degree of coupling can be easily changed by combining the divided windings on each straight part of the magnetic path to change the leakage flux, so the saturation characteristics of the magnetic core can be adjusted and the normal mode noise can be attenuated. The effect can be adjusted, and the industrial effect of the present invention is extremely great.

[Brief description of drawings]

1 and 3 are top views showing an embodiment of the common mode choke coil of the present invention, FIG. 2 is a curve diagram showing the frequency dependence of the attenuation amount with respect to common mode noise, and FIG.
FIG. 5 is a curve diagram showing the frequency dependence of the attenuation amount with respect to normal mode noise, FIG. 5 is a top view showing a conventionally used common mode choke coil, and FIG. 6 is a conventionally used common mode choke coil. It is a top view which shows the other example. 1 ... Regular octagonal closed magnetic circuit core, 2 ... first coil, 3 ...
… Second coil, 4-11 …… Split winding, 12–19 …… Straight section of magnetic path.

Claims (2)

[Claims] 1. A common mode choke coil comprising a polygonal closed magnetic circuit magnetic core having at least 5 angles, and windings dividedly and intensively wound on a straight line portion of a magnetic path of the polygonal closed magnetic circuit magnetic core. 2. The saturation characteristic of the polygonal closed magnetic circuit core is changed by combining the windings wound on the straight line portion of the magnetic path of the polygonal closed magnetic circuit core to change the degree of coupling to change the leakage flux. 2. The common mode choke coil according to claim 1, wherein an attenuation effect on normal mode noise is adjusted.