JPH0257726B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a balun matching device used in an antenna input circuit of a television receiver.

``Prior Art'' Television tuners generally use an unbalanced impedance of 75Ω as the antenna input circuit impedance. Therefore, when receiving with a 300Ω balanced feeder, a balun matching device is required to convert the impedance from 300Ω to 75Ω.

The conventional balloon matching device, as shown in Fig. 7,
Bifilar coils 2, 2 are wound three turns each around a core 1 having an ellipsoid with two through holes.
Then, as shown in Figure 8, the four coils are
a, 3b, 3c, and 3d, one end of the coils 3a and 3d becomes the 300Ω connection terminals 4 and 5, and the other end becomes the 75Ω connection terminals 6 and 7. Also, 300Ω
On the side, the coils 3b and 3c are short-circuited, and the 75Ω side coils 3a and 3c, and 3b and 3d are short-circuited, respectively.
Furthermore, in some cases, the coil 3b on the 300Ω side,
The connection point 3c and the coil 3b on the 75Ω side may be short-circuited.

``Problems to be solved by the invention'' In the conventional balloon matching device shown in Fig. 7, the work of winding the bifilar coils 2 and 3 around the core 1 and connecting them at both ends is all done manually. automatic winding of the coil was impossible. Moreover, these balloon matching devices have to be assembled into antenna circuits and the like by hand, one by one, which is extremely difficult to work with.
Moreover, there was a problem of high assembly costs.

"Means for Solving the Problems" The present invention has been made to solve the above-mentioned problems of the conventional art. A coil is imprinted on the outer periphery of the hole, the leg of at least one of the cores split into at least two parts is fitted into the core leg insertion hole, and the other core is further combined to form a magnetic circuit. This is what happens.

``Operation'' Since the coil and core can be automatically assembled into the insulating film, a balloon matching device can be obtained without any manual effort. In addition, if the insulating film is made into a long and thin tape and continuous balloon matching devices are formed on it at regular intervals, the insulating film can be cut into one balloon matching device at a time and incorporated into the circuit. Therefore, automatic assembly is possible.

"Example" Examples of the present invention will be described below.

Reference numeral 8 denotes a flexible insulating film in the form of an elongated tape. The insulating film 8 is the balloon matching device 1
Dividing holes 11 are punched out on the outer periphery, leaving only a portion of the connecting portion 10, so as to form individual coil impression pieces 9. The connecting portions 10 are cut during assembly. Further, leg insertion holes 12 for the core 1 are punched out in the coil imprinting piece 9 in the same number as the leg parts. Furthermore, feed holes 13, 13, . . . are bored at regular intervals on both side edges 14, 14 of this insulating film 8.

Each of the coil imprinting pieces 9 has four lead wire connection lands 15, three turns each of first, second, third and fourth coils 3a, 3b, 3c,
3d, connection line 1 connecting these as shown in Figure 8.
6... are printed and wired. Further, when performing printed wiring, the mutually intersecting portions 17 can be connected by forming through holes 18 in the coil imprinting pieces 9 and using printed wiring printed on the back side. Furthermore, when through holes are not used, the connection may be made by using jumper wires to straddle the printed wiring, and a conventionally known technique can be used for this.

If the insulating film 8 is too thin or too soft and is inconvenient for assembly work, etc., as shown in FIG.
A hard insulating substrate 19 may be applied to the lower surface. Of course, the insulating substrate 19 is provided with a leg insertion hole 20 for the core 1.

In this way, the coils 3a, 3b, 3c, 3d
After printing, the core 1 divided into two parts is inserted and fixed into each of the coil imprinting pieces 9. This core 1 is
As shown in FIG. 2, a comb-shaped core 1a having four legs 21 is combined with a flat plate 1b. After these cores 1a and 1b are bonded with adhesive, or simply while they are in close contact with each other, the outer periphery is molded with resin 22 as shown in FIG. At this time, grooves 23 for handling are formed on both sides, and lead wires 4, 5, 6, and 7 connected to lands 15 on the coil impression pieces 9 are led out from the molded resin 22.

In FIG. 2, the core 1 has a comb shape 1a with four legs and a flat plate shape 1b, but as shown in FIG.
The same core 1 as shown in FIG. 2 can be formed by simply combining two pieces. Furthermore, the shape of the core 1 is not limited to four legs, but may be one using E-shape 1a and I-shape 1b as shown in FIG. 4, or an elliptical shape with two holes 1c as shown in FIG.
Core 1a, 1 formed by dividing 1d into two
The core may have three legs 21 using a.

"Effects of the Invention" Since the present invention is constructed as described above, the manufacturing of the coil, the assembly of the core, the connection of the lead wires, etc. are all automatically performed, and no manual work is required at all. Therefore, a product with extremely good workability and uniform and stable properties can be obtained at a low cost.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an insulating film for explaining the balloon matching device according to the present invention, Fig. 2 is a sectional view taken along line A-A, Fig. 3 is a perspective view after molding, Fig. 4,
5 and 6 are perspective views of other examples of the core, FIG. 7 is a perspective view of a conventional balloon matching device, and FIG. 8 is an electric circuit diagram. 1, 1a, 1b...core, 2...bi-fiera coil, 3a, 3b, 3c, 3d...coil,
4, 5, 6, 7...Connecting terminal, 8...Insulating film, 9...Coil imprinting piece, 10...Connection part, 11
...Division hole, 12,20...Leg insertion hole, 13...
...Feed hole, 14...Both side edges, 15...Lead wire connection land, 16...Connection line, 17...Intersection part,
18...Through hole, 19...Hard insulating board,
21... Leg portion, 22... Resin, 23... Concave groove.

Claims (1)

[Claims] 1. A core leg insertion hole is formed in the insulating film,
A coil is imprinted on the outer periphery of one of the core leg insertion holes, and the leg of at least one of the cores split into at least two parts is fitted into the core leg insertion hole. A balloon matching device characterized by forming a magnetic closed circuit by combining cores. 2. The balloon matching device according to claim 1, wherein the insulating film is in the form of an elongated tape, and balloon matching devices are continuously formed on the elongated insulating film at regular intervals.