JPH0325379Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the structure of a noise filter that prevents noise from flowing into the signal line of electronic equipment.

[Prior art]

Some noise filters used in electronic devices are made by winding a ferrite annular magnetic core. This type of noise filter includes a filter (hereinafter referred to as a common mode choke coil) that connects the signal line and the earth line (ground line).
A filter (hereinafter referred to as an ESD coil) that connects a plurality of signal lines and a ground line is known, but the above-mentioned common mode choke coil and ESD coil are generally mounted on the wiring board of electronic equipment and are used to connect signal lines and ground lines. Connected to line and ground line. By the way, the space on the wiring board where these coils should be placed is extremely narrow, so
In the case of ESD coils, it is extremely troublesome to connect them to the signal line, and because these coils are arranged vertically (the radial direction of the magnetic core and the board are at right angles), they are unstable and susceptible to vibrations, etc. There is also the problem that the connection line (lead wire) between the signal line and the noise filter may be disconnected. Furthermore, since the winding wire is wound directly on the core, there is also the problem of insulation resistance.

[Purpose of invention]

An object of the present invention is to provide a noise filter that can be stably mounted on a wiring board, has improved insulation resistance, and is easily connected to the signal line of the wiring board.

[Structure of the idea]

According to the present invention, a magnetic core is housed in an insulating ring-shaped case, and a winding is applied to the case,
The above case has a mounting plate that can be placed in close contact with the wiring board, and the mounting plate has lead pin terminals for connecting to the above winding and to the wiring pattern of the above wiring board. A noise filter having the structure provided is obtained.

[Example of idea]

The present invention will be explained below with reference to embodiments shown in the drawings.

First, with reference to FIG. 1, the illustrated insulating case 1
To explain, the outer cylinder 1 concentric with the inner cylinder 11
2 is arranged, and one end (left side in the figure) of the outer cylinder 12 is provided with a lid part (not shown) that covers the space formed by the inner cylinder 11 and the outer cylinder 12. In other words, the inner cylinder 11 and the outer cylinder One end side of the space formed by 12 is closed in advance. The other end is covered with a lid 13 after a ferrite magnetic core 2 described later is placed thereon. The side surface of the outer cylinder 12 has the same width as the length of the outer cylinder 12.
A mounting plate 14 extending in the radial direction is provided integrally with the outer cylinder 12. (As shown in FIG. 2b, the width of the mounting plate 14 may be longer than the length (width) of the outer cylinder 12.) Furthermore, a noise filter using this insulating case is mounted on the lower surface of the mounting plate 14. A plurality of lead pin terminals 15 are implanted in the same pattern as the wiring pattern of the wiring board (not shown) to be placed (in FIG. 1, the lead pin terminals 15 are arranged along the long sides of the mounting plate 14). (Terminal 15 is provided.)

This insulating case 1 is made by arranging the annular ferrite magnetic core 2 as shown in the figure and then attaching the lid 13.
It becomes an insulated magnetic core.

This insulated magnetic core is provided with a winding 3 by wrapping one end of the conductor around an arbitrary lead pin terminal 15 arranged on one long side of the mounting plate 14, as shown in FIGS. 2a and b. The other end is tied to any lead pin terminal 15 arranged on the other long side. In this way, a plurality of windings 3 are applied to this insulated magnetic core,
It becomes an ESD coil. That is, as shown in FIG. 3, a plurality of coils 4 are formed from one insulated magnetic core.

The ESD coil described above is placed on a wiring board that should prevent noise. Then connect the ground line and signal line. At this time, the ESD coil is placed closely on the wiring board by means of a mounting plate, and the lead pin terminals pass through the wiring board and are soldered to the ground line or signal line on the back side of the wiring board.

[Effect of idea]

As explained above, in the noise filter according to the present invention, the magnetic core is housed in a ring-shaped case and the wire is wound around the ring-shaped case, so that insulation resistance is improved.
Moreover, it has a mounting plate that fits closely to the wiring board, and this mounting plate has lead pin terminals for connecting to the wiring pattern, so it is easy to connect the signal line, etc. of the wiring board to the noise filter, and it also fits tightly to the wiring board. Since it can be placed on the noise filter itself, excessive force is not applied to the noise filter itself due to vibrations, etc., and therefore, there is no possibility of wire breakage or the like.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a case where a ferrite magnetic core is housed in an insulating case used in the present invention;
Figure a is a front view showing one embodiment of the noise filter according to the present invention, Figure 2 b is a side view showing one embodiment of the present invention, and Figure 3 is an equivalent circuit of the noise filter shown in Figures 2 a and b. It is. 1... Insulating case, 11... Inner cylinder, 12...
Outer tube, 13... Lid, 14... Mounting plate, 15...
Lead pin terminal, 2...Annular ferrite magnetic core, 3
...Winding, 4...Coil.

Claims (1)

[Scope of utility model registration request] An insulating ring-shaped case in which a ring-shaped hollow part is formed, a ring-shaped magnetic core housed in the hollow part, and a mounting plate that is integrally attached to the case and placed in close contact with a wiring board. and a winding wound around the case, and the mounting plate is provided with a lead pin terminal connected to the winding and to the wiring pattern of the wiring board. Structure of noise filter.