JPH0448016Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a matching box used in an antenna input circuit of a television receiver.

(Prior Art) In general, tuners for television receivers use an unbalanced type impedance of 75Ω as the impedance of the antenna input circuit. Therefore, when receiving with a 300Ω balanced feeder, 300Ω to 75Ω
A matching device is required to convert the impedance.

As an electric circuit of such a matching box, for example, the third
As shown in the figure, magnetically coupled coils 1 and 2,
3 and 4, one end 1 of the coils 1 and 4
a, 4a are connected to the 300Ω connection terminals 5, 6, the other ends 1b, 4b are connected to the 75Ω connection terminals 7, 8, and the four ends 2a, 2 of the coils 2, 3 are connected to the 300Ω connection terminals 5, 6.
three ends 2a, 2b of b, 3a, 3b,
After the ends 3a are combined together, they are connected to one of the 75Ω connection terminals 7 and 8, and the remaining end 3b is connected to the other connection terminal 7. Conventionally, as shown in FIG. 4, the above-mentioned matching device is constructed by winding bifilar coils 10 and 11 three times each around a core 9, which is a long cylindrical body with two through holes. The four coils 1, 2, 3, shown in
4, and the ends 1a and 4a of the coils 1 and 4 are
Tie around the legs 5a, 6a of the 300Ω connection terminals 5, 6 and temporarily secure them, and then connect the ends 2a, 2b of the coils 2, 3, 4,
After twisting 3a and 4b, connect the 75Ω connection terminal 7,
Tie it around the leg 8a of one of the connecting terminals 8 of 8 and temporarily secure it, then tie the ends 1b and 3b of the coils 1 and 3, and then
Leg 7 of the other connecting terminal 7 of the 75Ω connecting terminals 7 and 8
It was tied around a and temporarily fixed, and then fixed by soldering. In this way, the ends of the coil were tied together and then temporarily attached to the legs of the connection terminal and fixed by soldering, which resulted in manual assembly, which was complicated and resulted in an increase in costs. In order to improve this drawback and simplify the assembly work by omitting the twisting and binding of the ends of the coil, the present applicant has filed a patent application No. 59-275846, as shown in Fig. 5.
There is a matching device manufactured by the invention of No. This matching box is connected to each end 1a, 1 of the coils 1, 2, 3, 4.
b, 2a, 2b, 3a, 3b, 4a, 4b and
300Ω connection terminal 5, 6 or 75Ω connection terminal 7,
8, the ends 1a, 1b, 2a, 2b, 3a, 3b, 4a, 4 of the coils 1, 2, 3, 4
b is omitted and each end is soldered and fixed to the printed wiring 13 of the printed circuit board 12, and the printed circuit board 12 has 300Ω connection terminals 5, 6 and
Legs 5a, 6a, 7a, 8 of 75Ω connection terminals 7, 8
A hole is drilled in which the part a is fixed by soldering.

(Problem to be solved by the invention) However, at least 300Ω connection terminal 5,
The legs 5a, 6a of the connecting terminals 5, 6 are cut off from the carrier using the chained terminals 6, and the ends of the feeder wire connecting screws are crushed or notched to prevent them from coming off. Therefore, the base material of the cut ends of the legs 5a and 6a of the 300Ω connection terminals 5 and 6 and the tip of the feeder wire connection screw will be exposed, and there is a risk that rust will occur from the cut ends and tips. However, there were problems in that the printed wiring 13 was shot and alignment performance was deteriorated. Therefore, in the past, brass was used as the material for the connection terminals to eliminate the inconvenience caused by rust.
There was a problem that the cost of materials increased.

The present invention was developed by focusing on these points, and by coating the cut ends of the legs and the tips of the screws for connecting feeder wires with solder, rust is less likely to occur on the cut ends and the tips of the screws for connecting feeder wires. Eliminate occurrence,
It is an object of the present invention to provide a matching device that can use materials of low cost.

(Means for solving the problem) Therefore, in the present invention, the end of the coil of the balun transformer is inserted into a predetermined insertion hole of a printed circuit board, and the lower surface of the printed circuit board is immersed in a solder solution bath. In a matching device in which the ends of the coils are soldered to form a twisted connection, the printed circuit board is coated with solder in the solder solution bath so that the legs of the connection terminals and the ends of the feeder wire connection screws are coated with solder in the solder solution bath. This matching device is characterized in that it is formed so as to extend to the soldering surface.

(Function) With this configuration, even if the material at the leg of the connection terminal and the tip of the feeder wire connection screw is exposed, the end of the coil can be soldered at the same time when it is connected to the printed circuit board by soldering. This can prevent rust from forming.

(Example) Next, an example of implementation of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view according to the present invention, and FIG. 2 is a front view showing a chain of connecting terminals. In the figure, reference numeral 20 denotes a matching device, which includes a housing body 21, a cap 22 that fits into the bottom opening of the housing body 21, a 75Ω connection terminal 23 that passes through the housing body 21, and a matching device that connects the housing body 21. 300Ω connection terminal 24 passing through,
It is composed of a balun transformer 25 and a printed circuit board 26.

The 75Ω connection terminal 23 is provided in a coaxial connector portion 27 protruding from one side of the housing body 21, and the 300Ω connection is cut from the chain connection terminal forming member as shown in FIG. The terminal 24 is provided in a feeder wire connector section 28 on one side of the housing body 21. Said 75Ω
The leg portions of the center conductor 23a and the ground conductor 23b of the connecting terminal 23, the leg portion 24a of the 300Ω connecting terminal 24, and the end portion of the coil 25a of the balun transformer 25 are connected to each other, which are formed on the printed circuit board 26. The tip of the feeder wire connection screw 24b of the 300Ω connection terminal 24 extends to the soldering surface of the printed circuit board 26.

To assemble the matching device 20 configured in this way, insert the 75Ω connection terminal 23 from the coaxial connector portion 27 on one side of the housing body 21, cut the terminal portion from the carrier of the chain connection terminal forming member, and make a 300Ω connection. A terminal 24 is formed and inserted from the feeder wire connector section 28. Then, the center conductor 23a of the 75Ω connection terminal 23 and the ground conductor 23
Insert the legs 24a of the 300Ω connection terminal 24, and the coil 25a of the balun transformer 25 into the insertion hole 26a of the printed circuit board 26, and solder the feeder wire connection screw 24b to the printed circuit board 26. Extend it to the surface and crush the tip to prevent it from falling out. Thereafter, the printed circuit board 26 of the housing body 21 with the cap 22 unfitted is immersed in a solder solution bath with its soldering side facing down, and the coil 25a and the 300Ω connection terminal 2 are immersed in the solder solution bath.
The leg portion 24a of No. 4 is soldered to the printed circuit board 26, and the tip of the feeder wire connecting screw 24b is coated with solder to prevent the feeder wire connecting screw from coming off. Although the plating will come off by crushing the tip of the feeder wire connection screw 24b, the peeled portion of the plating will be covered with solder coating. After the solder coating is completed, the cap 22 is fitted into the opening of the housing body 21 to complete the assembly of the matching device 20.

Note that the present invention is not limited to the above-mentioned embodiments; for example, a slit may be formed at the tip of the screw for connecting the feeder wire to prevent it from coming off, and this slit may be coated with solder. This increases the surface area of the tip of the feeder wire connecting screw, so that the feeder wire connecting screw cannot be pulled out from the housing body.

(Effects of the invention) The present invention is constructed as described above, and when soldering the end of the coil of a balun transformer to a printed circuit board, it can also be used on the cut-off end face of the leg of the connection terminal or the tip of the screw for connecting the feeder wire. Since solder coating can be applied, there is no risk of rust forming on the cut end of the connection terminal or the part where the plating on the tip of the feeder wire connection screw has peeled off, making it possible to use connection terminals and feeder wire connection screws made of inexpensive materials. The effect is that it can be used.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the matching device according to the present invention, Fig. 2 is a front view showing the connection terminal used in the invention, Fig. 3 is a circuit diagram of the matching device, and Fig. 4 5 is a perspective view showing a conventional balun transformer, and FIG. 5 is a longitudinal sectional view showing a conventional matching device. 20... Matching box, 23, 24... Connection terminal, 2
4a...Legs, 24b...Feeder wire connection screw, 25...Balun transformer, 26...Printed circuit board.

Claims (1)

[Scope of utility model registration request] The end of the coil of the balun transformer is inserted into a predetermined insertion hole of a printed circuit board, and the lower surface of the printed circuit board is immersed in a solder solution bath to solder the end of the coil to make a connection. In the matching device, the legs of the connection terminals and the tips of the feeder wire connection screws are formed to extend to the soldering surface of the printed circuit board so as to be coated with solder in the solder solution bath. Matching box.