JPH02277203A - Choke coil for common mode use - Google Patents

Abstract

PURPOSE:To surely execute a multiple split winding operation without using a bobbin and to make a magnetic flux distribution of a leakage flux comparatively uniform by a method wherein a polygonal closed magnetic circuit magnetic core of at least a pentagon or more is used and this choke coil is constituted by splitting and concentrating windings on individual straight-line parts of a magnetic path. CONSTITUTION:Split windings 4 to 7 of a first coil 2 are wound on straight-line parts 12 to 15 of a magnetic path of an octagonal closed magnetic circuit magnetic core 1. Then, split windings 8 to 11 of a second coil 3 are wound on straight-line parts of a magnetic path of the same magnetic core 1. However, winding directions of the two coils 2, 3 are set in such a way that they offset a magnetic flux generated by a line current. Thereby, since a structure to reduce a distributed capacitance is formed, it is very effective for an attenuation amount in a high-frequency region against a common-mode noise even when an inductance identical to that of conventional constitutions is in addition, even when a bobbin is not used, a split winding operation can be executed surely when the required number of straight-line parts of the magnetic path are available.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention is applicable to the prevention of power supply noise (common mode), for example.
This relates to choke coils for use in other applications.

BACKGROUND TECHNOLOGY In general, a non-motor choke coil is constructed by using two coils 40.4 as shown in FIG. 6 to prevent the magnetic flux generated by the line current from magnetically saturating the ring-shaped closed magnetic circuit magnetic core 39.
1 has a structure in which wires are wound in directions that cancel out the magnetic flux generated by line current, and most of the closed magnetic circuit cores conventionally used for this are ring-shaped closed magnetic circuit cores as shown in Figure 6. In addition, a rectangular closed magnetic circuit magnetic core 42 shaped like a mouth or sun as shown in FIG. 6 is used.

Problems to be Solved by the Invention In the above configuration, when a conventional ring-shaped closed magnetic circuit magnetic core 39 is used, the circumference of the outer diameter of the magnetic core is different from that of the inner diameter of the magnetic core, so the number of turns of the coils 40 and 41 is increased. The windings intersect on the inner diameter side of the magnetic core, making winding work extremely difficult. Furthermore, when the number of turns is increased and multilayer winding is performed, the potential difference increases and the distribution pattern increases, which deteriorates the high frequency characteristics of the common mode noise attenuation amount, which is the original role. Therefore, the 6th
As shown in the figure, when a rectangular closed magnetic circuit magnetic core 42 is used, a straight part is created in the fine connection, so using a bobbin 43 etc. makes winding easier, but since the magnetic path is a square or rectangular quadrangle, A right-angled portion is formed on the magnetic path, and leakage magnetic flux is concentrated at the right-angled portion, which may adversely affect nearby inductance components. In addition, when performing split winding, it is difficult to split unless the bobbin 43 is used.
If you try to divide it reliably without using a bobbin, you will only be able to divide it into three parts even if you use the four sides properly.

In view of the above-mentioned problems, the present invention simplifies the work of winding one wire, reduces distributed capacitance, improves high-frequency characteristics, and allows reliable unwinding even without using a bobbin, and the magnetic flux distribution of leakage flux is relatively uniform. The present invention provides a common mode choke coil that is easily modified.

Means for Solving the Problems In order to solve the above problems, the present invention uses a polygonal closed magnetic circuit core having at least a hexagonal shape, and is constructed by dividing and concentrating windings on each straight portion of the magnetic path. It is something.

Effect According to the above means, the winding work is facilitated by creating straight sections in the magnetic path, and by concentrating a certain number of turns on each straight section of the magnetic path, the total number of turns is divided, and the potential difference is reduced. By becoming smaller, distributed capacitance can be reduced and high frequency characteristics can be improved. Moreover.

Even without using a bobbin, if you have as many straight sections of the magnetic path as you want to divide, you can not only reliably perform divided winding, but also because the corners are obtuse, the distribution of magnetic flux leaking from the corners will be dispersed and around one area. Even when inductance components are placed in In addition, the degree of coupling can be easily changed by combining the windings divided on each straight part of the magnetic path, so this will change the leakage flux and adjust the saturation characteristics of the magnetic core. It is also possible to adjust the damping effect.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a top view showing one embodiment of a common mode choke coil according to the present invention. The first coil 20 divided windings Is4, 6, 6.7 are applied to the straight portions 12, 13, 14°16 of the magnetic path of the octagonal closed magnetic path magnetic core 1. Next, a second coil 30-divided winding 8°9.10.11 is applied to the straight portion 16°17.18.19 of the magnetic path of the magnetic core 1. However, the winding directions of the two coils 2.degree. 3 are such that the magnetic flux generated by the line current is mutually canceled out.

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 M is due to the common mode choke coil of FIG. Coil 1 in Figure 1
The same inductance value at 0KH2 is constructed using the conventional ring-shaped closed magnetic circuit core shown in Fig. 6, and B
This curve shows the coil having the same inductance value at 10 KHz as the coil shown in FIG. 1, but constructed using the conventional rectangular closed magnetic circuit core shown in FIG. However, all three types of closed magnetic circuit magnetic cores are made of the same material and have the same weight. Also 1
When measuring the leakage flux at oKHz, the common mode choke coil of the present invention has a 62 μH for a coil inductance value of 5 mH, 1 has a conventional ring-shaped closed magnetic circuit core, has a 43 μH, and has a conventional rectangular closed magnetic core. The one used was 120 μH. In this example, a regular octagonal closed magnetic circuit core 1 was used, but the same effect can be obtained by using a hexagonal or larger polygonal closed magnetic circuit core, and the number of corners depends on the desired number of winding divisions and magnetic flux. It may be determined based on the leakage distribution, etc.

Next, an embodiment will be described with reference to the drawings in which the degree of coupling is changed by combining each of the four windings wound on the straight 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 portions 12 to 19 of the magnetic path. Next, four of these eight windings are arbitrarily selected and 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 30 are set so as to cancel out the magnetic flux generated by the line current. In FIG. 3, the windings 4.6, 9.11 are the first coil 2, and the windings 5, 7, 8.10 are the second coil 3. According to the connection shown in Figure 3, the leakage magnetic flux when the degree of coupling is 9.10 KHz is 2 for the coil inductance value csmH.
It was 0μH. Furthermore, by changing the combination of windings, the deflection magnetic flux of the common mode choke coil shown in FIG. 3 could be set to any value between 20 and 62 μH.

FIG. 4 is a diagram showing the amount of attenuation of the common mode choke coil according to an embodiment of the present invention against normal mode noise.
The curve for which the leakage magnetic flux is 40μH1F is the leakage magnetic flux of 6
This is due to the 2μH.

Effects of the Invention As detailed above, the common mode choke coil according to the present invention has linear portions in the magnetic path to facilitate winding work, and a certain number of turns can be concentrated on each straight portion of the magnetic path. Since the total number of turns is divided by winding, the structure reduces the distributed capacitance, so it is very effective in attenuating common mode noise in the high frequency range while obtaining the same inductance as the conventional structure. . Moreover, even if you do not use a bobbin, you can not only reliably perform divided winding as long as there are as many straight sections of the magnetic path as you want to divide, but since the corners are obtuse, the distribution of magnetic flux leaking from the corners will also be dispersed. , even when inductance components are placed around the device, it is less likely to have an adverse effect.

In addition, by combining the windings divided on each straight part of the magnetic path, the degree of coupling can be easily changed and leakage flux can be changed, so the saturation characteristics of the magnetic core can be adjusted to attenuate normal mode noise. You can adjust the effect,
The industrial effects of the present invention are said to be extremely large.

[Brief explanation of drawings]

1 and 3 are top views showing one embodiment of the common mode choke coil of the present invention, FIG. 2 is a curve diagram showing frequency dependence of attenuation amount for common mode noise, and FIG.
The figure is a curve diagram showing the frequency dependence of the attenuation amount for normal mode noise, Figure 6 is a top view showing a conventionally used common mode A-ch coil, and Figure 6 is a conventionally used common mode FIG. 7 is a top view showing another example of a choke coil. DESCRIPTION OF SYMBOLS 1...Regular octagonal closed magnetic circuit core, 2...First coil, 3...Second coil, 4-11.
...Split winding. 12-19... Straight portion of the magnetic path. Name of agent: Patent attorney Shigetaka Awano and 1 other person @1
Figure 2 Frequency rMHx) Figure 2 Frequency rMHx)

Claims (2)

[Claims] (1) A common mode choke coil that uses a polygonal closed magnetic circuit core having at least a pentagonal shape and is constructed by dividing and intensively winding a winding on the straight portion of the magnetic path of the closed magnetic circuit core. (2) By combining each winding wound on the straight part of the magnetic path of the closed magnetic circuit magnetic core, the degree of coupling is changed and the leakage magnetic flux is changed, thereby adjusting the saturation characteristics of the magnetic core and suppressing normal mode noise. 2. The common mode choke coil according to claim 1, wherein the damping effect of the common mode choke coil is adjusted.