JPH0626232U - choke coil - Google Patents

Abstract

(57) [Abstract] [Purpose] By forming a plurality of coils in one core, the number of parts is reduced to facilitate assembly work, and the space required for arranging choke coils is reduced. A structure is characterized in that a plurality of winding windows are provided in a core, a winding is continuously wound around each winding window, and a plurality of coils are equivalently formed in one core. [Effect] Since a desired characteristic can be obtained with one choke coil, the number of parts can be reduced and the assembling work can be facilitated. Moreover, the space for disposing the choke coil is reduced, and the substrate area can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a choke coil for absorbing noise, in which a plurality of coils are formed in one core.

[0002]

[Prior art]

 A toroidal coil is generally used as the choke coil for noise removal provided at the input / output end of the electronic device. FIG. 5 shows a perspective view of this toroidal choke coil. Two windings 2 are wound around an annular core 10 to form a coil 11. Reference numerals 5A, 5B, 6A, and 6B respectively represent input / output terminals.

FIG. 6 shows an equivalent circuit when the choke coil shown in FIG. 5 is actually used. 5 and 6, the parts having the same functions are given the same numbers. The choke coil 11 is incorporated in the electronic device 12, and its output terminals 6A and 6B are connected to the circuit of the electronic device 12, and the input terminals 5A and 5B are connected to the signal transmission line 13. .

FIG. 7 shows frequency characteristics of impedance appearing between the input / output terminals 5A and 6A of the choke coil shown in FIG. 5 or between the input / output terminals 5B and 6B. As shown in FIG. 6, when a single choke coil 11 is used, the frequency characteristic of the impedance of the choke coil 11 is as shown by the solid line in FIG. Assuming that the impedance value that can effectively reduce noise is Z _X , it can be seen from the frequency characteristics of FIG. 7 that the effective frequency range of noise reduction when using a single choke coil is f _{7 to} f _8. .

However, since the frequency band of the actual noise signal is wide, only a part of noise can be reduced by a single choke coil. Usually, in order to reduce noise over a wide frequency band, a plurality of choke coils are connected in series and used. The frequency characteristics of impedance when a plurality of choke coils are connected in series are shown by the broken line in FIG. Thus, by connecting the Cho Kukoiru series a plurality, effective frequency range that noise can be reduced as compared with the case of using f ₉ ~f _10, and the choke coil in the singular, reducing a wide range of noise be able to.

However, the use of a plurality of choke coils increases the number of parts, and also requires the work of connecting the respective coils, which increases the number of assembling steps. Further, there is a problem that the space required for arranging the choke coil increases and the substrate area increases.

[0007]

[Problems to be solved by the device]

 The present invention has been made in view of the problems of the conventional toroidal choke coil. The object of the present invention is to reduce the number of parts to facilitate the assembling work and to reduce the space required for arranging the choke coil. And

[0008]

[Means for Solving the Problems]

 The present invention is a choke coil that is connected to the input / output terminals of an electronic device to reduce noise that enters the electronic device from the signal line and noise that leaks from the electronic device to the signal line. Is provided, a winding is continuously wound around each of the winding windows, and a plurality of coils are equivalently formed in one core.

[0009]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a perspective view of the choke coil of the present invention. Two winding windows 3A and 3B are opened in the core 1. The winding 2 made of two conductors is first wound around the winding window 3A of the core 1 and the outer peripheral portion of the core to form the coil 4A, and further wound continuously around the winding window 3B and the outer peripheral portion of the core. Then, the coil 4B is formed. 5A and 5B are input terminals, and 6A and 6B are output terminals. The parts having the same functions as those in FIG. 5 described in the conventional example are denoted by the same reference numerals.

The choke coil wound as described above is represented by an equivalent circuit as shown in FIG. 2, in which the coils 4 A and 4 B formed in the two winding windows of the core 1 are connected in series. Thus, a circuit similar to the case where two toroidal choke coils described in the conventional example are connected in series can be obtained. FIG. 3 shows frequency characteristics of impedance between the input / output terminals 5A and 6A of the choke coil shown in FIG. 1 or between the input / output terminals 5B and 6B. L _A shows the frequency characteristic of the impedance of the coil 4A formed in the winding window 3A, and L _B shows the frequency characteristic of the impedance of the coil 4B formed in the winding window 3B. L _{A + B} shows the frequency characteristics of the choke coil of the present invention, which is a combination of the impedances of the coil 4A and the coil 4B.

An impedance value that can effectively reduce noise is Z_XThen, if the coil 4A or 4B is used alone, the effective frequency range for noise reduction is f₁~ F₂Or f₃~ F _Four However, looking at the choke coil of the present invention as a whole, the effective frequency range is f_Five~ F₆Therefore, the noise can be reduced over a wide frequency band.

As described above, according to the embodiment shown in FIG. 1, one choke coil having one core can obtain an effective frequency range of noise reduction equivalent to the case where two toroidal choke coils are connected in series. be able to. Therefore, since the required effective frequency range for noise reduction can be covered by one choke coil, the number of parts can be reduced. In addition, compared to the conventional product, in which multiple coils are wound and connected in series, only one coil winding operation is required, and since there is no work to connect the coils, the assembly man-hours are significantly reduced. Can be reduced to

In the embodiment of FIG. 1, the case where the core 1 is provided with the two winding windows 3A and 3B has been described. However, when desired characteristics are obtained, two or more winding windows are provided. A line window may be provided. Further, the two windings 2 are wound at the same time, but the number of windings is not limited to this.

FIG. 4 shows a sectional view of another embodiment of the present invention. The choke coil winding window of the present invention shown in FIG. 1 was formed by providing a hole penetrating the core. The choke coil shown in FIG. 4 has winding windows 9A, 9B, 9C and 9D formed by combining a core 7 and an I-shaped core 8 each having a comb-shaped cross section, and winding coils 10A, 10B and 10C. It has a structure that facilitates turning.

[0015]

[Effect of device]

 As described above, the choke coil of the present invention has a plurality of winding windows provided in one core to form a plurality of coils. As a result, the number of parts is smaller than that of the conventional one in which a plurality of choke coils are connected in series to obtain desired characteristics, and the assembling work can be facilitated. Moreover, since a desired characteristic can be obtained with one choke coil, the space for arranging the choke coil is reduced, and the substrate area can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the choke coil of the present invention.

FIG. 2 is an equivalent circuit diagram of the choke coil of FIG.

3 is a frequency characteristic of impedance of the choke coil of FIG.

FIG. 4 is a cross-sectional view of another embodiment of the choke coil of the present invention.

FIG. 5 is a perspective view of a conventional choke coil.

FIG. 6 is an equivalent circuit diagram when the choke coil of FIG. 5 is actually used.

7 is a frequency characteristic of impedance of the choke coil of FIG.

[Explanation of symbols]

 1 core 2 winding 3A, 3B winding window 4A, 4B coil 5A, 5B input terminal 6A, 6B output terminal 7 comb-shaped core 8 I-shaped core

Claims (1)

[Scope of utility model registration request] 1. A choke coil connected to an input / output terminal of an electronic device to reduce noise entering a signal line into the electronic device and noise leaking from the electronic device to the signal line. A choke coil characterized in that a plurality of coils are equivalently formed on one core by winding a winding continuously around each winding window.