JPH0317458Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) This invention relates to a noise filter, and particularly to a noise filter in which a coil and a capacitor connected to the coil are housed in a case, and terminals are formed in the case.

(Prior Art) FIG. 4 is a plan view showing an example of a conventional noise filter of this type. This noise filter 10 includes a box-shaped case 12 made of, for example, synthetic resin. A coil bobbin 14 is fixed within the case 12 with adhesive, for example. Two coils 16a and 16b are wound around the coil bobbin 14,
A mutual induction circuit is constructed. The coil bobbin 14 also has four coil bobbin terminals 14a, 14.
b, 14c and 14d are formed. and,
The coil 16a is connected to the coil bobbin terminals 14a and 14d, and the coil 16b is connected to the coil bobbin terminal 14.
b and 14c, respectively. Further, a core 18 is inserted through the bobbin 14.

On the other hand, two input terminals 20 and 24 and one ground terminal 22 are fixed to one side of the case 12. Further, two output terminals 26 and 28 are fixed to the other side of the case 12. Then, between the terminals 14a and 20, the terminal 14
The terminals b and 24, the terminals 14c and 26, and the terminals 14d and 28 are connected by lead wires, respectively. Further, between terminals 20 and 22, between terminals 22 and 24, and between terminals 26 and 2
8, capacitors C1, C2 and C3 are connected between them, respectively.

This noise filter 10 has a circuit configuration shown in FIG.

(Problems to be Solved by the Invention) The conventional noise filter 10 has a large number of terminals, requires lead wires to connect the terminals, and further requires a process of soldering the lead wires. It's complicated.

Therefore, the main purpose of this invention is to provide a noise filter with a simple configuration by reducing the number of terminals.

(Means for solving the problem) This invention includes a case, a coil bobbin housed in the case, and a plurality of terminals extending from the coil bobbin to the outside of the case and shared with input terminals and output terminals. , a coil wound around a coil bobbin and connected to the input terminal and output terminal, a ground terminal provided through the case, a capacitor connected between the input terminal and the ground terminal inside the case, and an output terminal inside the case. A noise filter that includes a capacitor connected between terminals.

(Effect of the invention) Since the terminal attached to the coil bobbin is extended to the outside of the case and shared with the input terminal and the output terminal, a noise filter with a small number of terminals can be obtained. Furthermore, the lead wires used in the conventional connection between terminals are no longer required, and the step of soldering the lead wires is no longer necessary, making assembly easier.

Furthermore, since lead wires are not used, there is no need for space for lead wires, which not only enables miniaturization, but also improves the reliability of the noise filter as there is no risk of the lead wires coming into contact with other parts. do.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Embodiment) FIG. 1 is a plan view showing an embodiment of this invention. This noise filter 10 includes a box-shaped case 1 made of, for example, synthetic resin or insulated metal.
Contains 2. Notches 12a and 12b are formed on one side of the case 12, and cutouts 12c and 12d are formed on the other side. Terminals 30, 32, 34, and 36 formed on the coil bobbin 14, which will be described later, are fitted into these notches 12a to 12d.

The coil bobbin and its surrounding parts will be explained with reference to FIG.

The coil bobbin 14 is made of, for example, a hollow cylindrical insulating material, and has flanges 1 at both ends and in the center.
4a, 14c and 14b are formed. A coil 16a is wound around this coil bobbin 14 in a winding groove on one side defined by flanges 14a and 14b, and a coil 16b is wound in a winding groove on the other side defined by flanges 14b and 14c.

Further, the lower part of the collar 14a is a flat surface, and the flat surface has terminals 30 and 36 extending perpendicularly to the axial direction of the coil bobbin 14 and in mutually opposite directions.
are integrally provided, for example, by molding. Similarly, terminals 32 and 34 are also formed on the flat surface of the collar 14c. The winding start of the coil 16a is connected to the terminal 30, the winding end of the coil 16a is connected to the terminal 36, the winding start of the coil 16b is connected to the terminal 34, and the winding end of the coil 16b is connected to the terminal 32.

Further, a core 18 is inserted through the coil bobbin 14. The core 18 is made up of two U-shaped magnetic bodies that are butted against each other in an annular shape, and both ends of the core 18 are provided with a spring 1.
It is held between 8a.

As shown in FIG.
In b, the terminal 34 is fitted into the notch 12c and the terminal 36 is fitted into the notch 12d, respectively, and the tips of the terminals 30, 32, 34 and 36 are brought out of the case 12. In this way, the coil bobbin 14 is housed in the case 12.

Further, another terminal 22 as a ground terminal is connected to the case 1 between the notches 12a and 12b of the case 12.
2. And capacitor C
1 is connected between the terminal 30 that is shared as an input terminal and the terminal 22 that is used as a ground terminal, a capacitor C2 is connected between the terminal 22 that is used as a ground terminal, and a terminal 32 that is also used as the input terminal, and a capacitor C3 is connected between the terminal 22 that is used as the ground terminal and the terminal 32 that is also used as the input terminal. Between the terminals 34 and 36 shared with the output terminal,
Each is connected.

Finally, as shown in FIG. 3, a top cover 38 is placed on the case 12 and fixed, for example, with adhesive.
At this time, the upper cover 38 allows the terminals 3 fitted into the notches 12a to 12d as described above to
0 to 36 can be pressed from above and held more stably.

In this way, the noise filter 10 shown in FIG. 3 is obtained, and its circuit configuration is as follows in this embodiment.
The circuit configuration is the same as that shown in FIG. 5 above.

It goes without saying that this invention can be arbitrarily applied to noise filters having various circuit configurations other than the circuit configuration of the above-described embodiment.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of this invention. FIG. 2 is a perspective view showing the coil bobbin of the embodiment shown in FIG. 1 and its surroundings. FIG. 3 is an overall external perspective view of the embodiment shown in FIG. FIG. 4 is a plan view showing an example of a conventional noise filter. FIG. 5 is a circuit diagram of this noise filter. In the figure, 10 is a noise filter, 12 is a case, 14 is a coil bobbin, 16a and 16b
is a coil, 18 is a core, 22, 30, 32, 34
and 36 are terminals, and C1, C2 and C3 are capacitors.

Claims (1)

[Claims for Utility Model Registration] A case, a coil bobbin housed in the case, a plurality of terminals extending from the coil bobbin to the outside of the case and shared with input terminals and output terminals, and a plurality of terminals wound around the coil bobbin. a coil connected to the input terminal and the output terminal; a ground terminal provided through the case; a capacitor connected between the input terminal and the ground terminal within the case; A noise filter that includes a capacitor connected between the output terminals.