JP2002198764A - Band reject filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a band reject filter that can easily be manufactured without the need for an electric wire cutting or winding work. SOLUTION: The band reject filter of this invention is manufactured by obtaining an inductive component by utilizing a primary winding of a transformer, providing an LC circuit connecting a capacitor in parallel with a secondary winding of the transformer, and clamping a ring shaped lead wire formed by connecting both ends of the capacitor and both ends of a lead wire together with a signal wire between the 2-divided cores so as to obtain an equivalent configuration to the circuit above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a band reject filter for removing only a frequency component in a certain band, and more particularly to a band reject filter which can be used for communication using an existing communication line such as a telephone line or a power line. It relates to a band reject filter.

[0002]

2. Description of the Related Art A conventional band reject filter will be described below. As a conventional general band reject filter, for example, there is a constant K-type band reject filter. The constant-K band reject filter has the general characteristics of a band reject filter in which the amplitude in the pass band is flat and the amplitude is attenuated in the attenuation band.

FIG. 7 is a diagram showing a circuit configuration of the constant K-type band reject filter. In FIG. 7, 100
Is a conventional constant-K band reject filter, and 10
1-1 to N, 103-1 to 103-N are coils,
1 to N, 104-1 to 104-N are capacitors, and here, a coil and a capacitor (for example, coil 101-1)
And the combination of the capacitor 102-1 and the coil 103-1 and the capacitor 104-1) are connected over N stages, and a desired band reject characteristic is obtained by adjusting C and L.

Here, a case will be described in which the band reject filter having the above circuit configuration is applied to, for example, power line communication. FIG. 8 is a schematic diagram of a main body of a general band reject filter. When applied to power line communication, it is necessary to temporarily disconnect an existing power line (signal line) (see a disconnection position in FIG. 8). That is, the power line is cut once, and a separately manufactured band reject filter is connected. Further, as shown in FIG. 8, a separately manufactured band reject filter requires a thick wire to be manually wound in a coil shape. Therefore, N
If the coils are connected in stages, this process is performed N times, and a large number of manufacturing steps are required. Note that a predetermined number of capacitors are connected between the signal line and the ground line.

[0005]

In the above-mentioned conventional band reject filter, the operation of cutting the electric wire, the operation of winding the electric wire in a coil shape, the operation of attaching the completed winding wire, and the like occur. Takes a long time. Also,
There is a problem that a power failure occurs with the cutting of the electric wire. In addition, when the number of stages of the filter is increased in order to enhance the performance, a time-consuming winding operation of the electric wire is increased, and there is a problem that the manufacturing time of the band reject filter is further increased.

When a conventional band reject filter is applied to a power line modem, all subscribers (each home)
However, there is a problem that costs such as labor costs increase because the above-mentioned work needs to be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and is a band reject filter that can be easily manufactured without cutting an electric wire, winding an electric wire, and without causing a power failure during installation. The purpose is to obtain.

[0008]

Means for Solving the Problems The above-mentioned problems are solved,
In order to achieve the object, in a band reject filter according to the present invention, an inductance component is obtained by using a primary winding of a transformer, and a capacitor is connected in parallel to a secondary side of the transformer. An LC type circuit is provided, and a ring-shaped lead formed by connecting both ends of the capacitor and both ends of the lead wire is sandwiched by the two-part core together with the signal line so as to be equivalent to the circuit configuration. It is characterized by the following.

The band reject filter according to the next invention is further characterized in that the LC type circuit is connected in a plurality of stages.

The band reject filter according to the next invention is characterized in that the LC type circuit is further provided on the ground side.

In the band reject filter according to the next invention, a combination of the LC type circuit on the signal line side and the LC type circuit on the ground side is connected in a plurality of stages. I do.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a band reject filter according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited by the embodiment.

Embodiment 1 FIG. FIG. 1 is a diagram showing a circuit configuration of a band reject filter according to the present invention. In FIG. 1, reference numeral 1 denotes a band reject filter of the present embodiment, reference numeral 2 denotes a transformer, and reference numeral 3 denotes a capacitor. Here, an inductance component is obtained by using a winding (coil) of the transformer 2; Transformer 2 2
The capacitor 3 is arranged in parallel with the next side,
A desired characteristic is obtained by adjusting the inductance and the capacitance.

Here, a case where the band reject filter having the above circuit configuration is applied to, for example, power line communication will be described. In the present embodiment, a transformer is configured with a two-piece core in consideration of workability.

FIG. 2 is a schematic diagram of the main body of the band reject filter (a form of a product to be provided). For example, when the band reject filter is applied to power line communication, a filter is manufactured using an existing power line. Therefore, in the related art, the existing power line (signal line) is once cut off at the manufacturing stage ( See FIG. 8). However, in the present embodiment, since the transformer 2 is constituted by the two-piece core, the power line is not cut off, and further, the capacitor is not connected between the signal line and the ground line, and the procedure is simple. Create a filter. More specifically, first, one lead wire covered with an insulator such as vinyl clothing is connected to both ends of the capacitor 3 in a ring shape. Then, a ring-shaped lead wire is set in the inner groove portion of the b portion of the two-piece core, and the power line is sandwiched between the a portion and the b portion of the two-piece core together with the lead wire.

As described above, in the present embodiment, a circuit configuration in which a capacitor and a coil using a winding of a transformer are arranged in parallel is provided. As a form to be actually provided, a power line and both ends of the capacitor are provided. The connected ring-shaped lead wire was sandwiched between two split cores. As a result, while achieving the same filter characteristics as the conventional band reject filter shown in FIG. 8, the production can be greatly facilitated as compared with the conventional band reject filter, so that the production time can be reduced.
As a result, it is possible to reduce costs such as labor costs.

As will be described later, the band reject filter may be configured in a plurality of stages to further improve the filter characteristics. For example, FIG. 3 is a diagram illustrating a circuit configuration of a band reject filter having a multi-stage configuration. In FIG. 3, reference numeral 1a denotes a band reject filter according to the present embodiment, 2a-1 to N denote transformers, and 3a-1 to N denote capacitors. Here, the transformer and the capacitor (for example, the transformer 2a- 1 and the capacitor 3a-1) are connected over N stages, and a desired characteristic is obtained by adjusting the inductance and the capacitance. Specifically, in the band reject filter shown in FIG. 3, if the resonance frequency is the same, the slope of the boundary between the pass band and the stop band becomes steeper than that of the band reject filter shown in FIG. 1, and the filter characteristics are improved. . Further, the bandwidth of the stop band can be widened by slightly shifting the resonance frequency of each stage. in this case,
The band reject filter that can be provided has a body shape as shown in FIG.

Further, in the present embodiment, the band reject filter of the present invention is applied to power line communication for convenience of explanation. However, the present invention is not limited to this. For example, a communication network such as a general telephone line or a LAN is used. Etc. may be applied.

Embodiment 2 In the present embodiment, from the viewpoint of further improving the filter characteristics, filters are arranged on both the signal line and the ground line to absorb the unbalanced component of the ground.

FIG. 5 is a diagram showing a circuit configuration of the band reject filter according to the present invention. In FIG. 5, 1
b is a band reject filter of the present embodiment,
2b-1 to N and 4b-1 to N are transformers, and 3b-
1 to N and 5b-1 to 5N are capacitors. Note that N =
The case of 1 shall be included.

The band reject filter 1b of the present embodiment has the configuration of the first embodiment also on the ground line side,
Then, similarly to the first embodiment, a desired characteristic is obtained by adjusting the inductance and the capacitance using the winding of the transformer. Further, as in the first embodiment, the transformer is constituted by a two-piece core as a form of a product to be actually provided.

FIG. 6 is a schematic diagram of the main body of a band reject filter that can be provided. This band reject filter can maintain the balance of the signal with respect to the ground as compared with the band reject filter of FIG.

As described above, in this embodiment, the circuit in which the capacitor and the coil using the winding of the transformer are arranged in parallel is provided on the signal line side and the ground line side, respectively. Also, as a form to actually provide,
A ring-shaped lead wire connecting both ends of a signal line and a capacitor and a ring-shaped lead wire connecting both ends of a ground line and a capacitor are sandwiched by two-piece cores. As a result, the production can be greatly facilitated as compared with the conventional art, so that the production time can be reduced and the labor and other costs can be reduced. Further, in addition to the advantages of the first embodiment, the common Mode filter characteristics can be improved.

[0024]

As described above, according to the present invention, according to the present invention, a circuit configuration in which a capacitor and a coil using a winding of a transformer are arranged in parallel is provided. And a ring-shaped lead wire having both ends connected to each other with a two-part core. As a result, the same filter characteristics as those of the conventional band reject filter can be realized, and furthermore, the production can be greatly facilitated as compared with the conventional band reject filter. The effect is that it can be done.

According to the next invention, since the combination of the transformer and the capacitor is configured in a plurality of stages, the inclination of the boundary between the pass band and the stop band can be made steep, so that the filter characteristics are greatly improved. The effect that it can be made to play is produced.

According to the next invention, the circuit in which the capacitor and the coil using the winding of the transformer are arranged in parallel is provided on the signal line side and the ground line side, respectively. Further, as a form actually provided, a signal line and a ring-shaped lead wire connected to both ends of a capacitor are sandwiched by a two-piece core, and a ground wire and a ring-shaped lead wire connected to both ends of a capacitor are further divided into two pieces. It was configured to be sandwiched between cores. As a result, the production can be greatly facilitated as compared with the related art, so that the production time can be reduced, and the cost such as labor cost can be reduced. In addition, since the configuration is such that the unbalanced component on the ground side is absorbed, it is possible to maintain the balance of the signal with respect to the ground.

According to the next invention, by connecting the combination of the configuration on the signal line side and the configuration on the ground side over a plurality of stages, the slope of the boundary between the pass band and the stop band can be made steep, It is possible to improve the filter characteristics while maintaining the balance of the signal to the ground,
This has the effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing a circuit configuration of a band reject filter according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a main body of the band reject filter according to the first embodiment.

FIG. 3 is a diagram illustrating a circuit configuration (different from FIG. 1) of the band reject filter according to the first embodiment of the present invention;

FIG. 4 is a schematic diagram of a main body of the band reject filter according to the first embodiment (different from FIG. 2).

FIG. 5 is a diagram showing a circuit configuration of a band reject filter according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram of a main body of a band reject filter according to a second embodiment.

FIG. 7 is a diagram showing a circuit configuration of a conventional band reject filter.

FIG. 8 is a schematic diagram of a main body of a conventional band reject filter.

[Explanation of symbols]

1, 1a, 1b band reject filter, 2, 2a
-1,2a-N, 2b-1,2b-N, 4b-1,4b
-N transformer, 3,3a-1,3a-N, 3b-1,
3b-N, 5b-1, 5b-N capacitors.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 27/28 H01F 15/00 D (72) Inventor Ken Araki 2-3-2 Marunouchi 2-chome, Chiyoda-ku, Tokyo (72) Inventor Yukio Hotta 7-7-1, Koriyama, Taishiro-ku, Sendai-shi, Miyagi F-term (reference) 5E043 AA01 EA01 EA05 5E070 AA05 BA18 CB18 DB06 5J024 AA01 BA18 CA04 CA06 DA26 DA34 EA05

Claims (4)

[Claims] 1. A band reject filter used to remove only a specific frequency component from an existing signal line, wherein an inductance component is obtained by using a primary winding of a transformer, and a secondary side of the transformer is provided. An LC-type circuit for connecting a capacitor in parallel to the circuit, and a ring-shaped lead formed by connecting both ends of the capacitor and both ends of the lead so as to be equivalent to the circuit configuration, A band reject filter sandwiched by a two-divided core together with a signal line. 2. The band reject filter according to claim 1, wherein said LC type circuit is connected in a plurality of stages. 3. The band reject filter according to claim 1, further comprising the LC type circuit provided on the ground side. 4. The band reject filter according to claim 3, wherein a combination of the LC type circuit on the signal line side and the LC type circuit on the ground side is connected in a plurality of stages.