JPS5821910A - Antenna connector - Google Patents

Abstract

PURPOSE:To ensure the free selection and application for a ribbon feeder of 300OMEGA or a coaxial cable of 75OMEGA through a switching operation of a changeover switch. CONSTITUTION:With use of a ribbon feeder 22 of 300OMEGA, a changeover tongue bar 41 is turned to be connected to a fitting receiver 46. Thus the matching of impedance of 300OMEGA-75OMEGA is attained by the function of a balun 21. As a result, an external antenna is connected to a TV picture receiver. When a coaxial cable 27 of 75OMEGA is used, the bar 41 is turned to release the matching to a fitting receiver 45. Then a slotting hole 43 is turned to the inserting direction of the cable 27, and a core wire 27a is put through the hole 43 for connection. At the same time, a shielding wire 27b is held between the holder pieces 33 and 34. Thus the matching is attained for the impedance of 75OMEGA-75OMEGA without receiving the effect of the balun 21. In such way, an external antenna can be connected to a TV picture receiver.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antenna connector that can selectively use a so-called balun, which is an impedance converter, depending on the impedance of a conducting wire connecting an external antenna and a television receiver. Currently, when connecting an external antenna and a television receiver, a balanced conductor wire having an internal resistance of 300 ohms, such as a ribbon feeder, or an unbalanced conductor wire having an internal resistance of 75 ohms, for example, a coaxial cable, is used. Since the internal resistance of the tuner of a television receiver is 75Ω, if a ribbon feeder of 300Ω is used, the
The connection is made through a so-called balun, which is a 00Ω to 75Ω conversion transformer, and impedance matching between the ribbon feeder side and the television receiver side is achieved. Furthermore, when using a 75Ω coaxial cable, it is necessary to match the impedance, so the cable is connected directly to the television receiver without using the balun.

Therefore, for television receivers that are widely used, it is possible to use either a 300Ω ribbon feeder or a 75Ω free shaft cable, as shown in the equivalent circuit in Figure 1. A standard antenna connector is used. This antenna connector has a balun 2 placed inside a synthetic resin molded case, and 300Ω input ends 5a and 5b are provided on the input side of the balun 2 to which conductors 4a and 4b of one and the other of the ribbon feeder 3 are connected. A 75Ω input terminal 8 to which a coaxial cable 7 is connected is provided on the 75Ω output terminal 6 side of the balun 2. Note that the 75Ω output terminal 6 has a 75Ω output terminal 7 whose one end is connected to the antenna terminal of the tuner in the television receiver 10.
A 5Ω coaxial cable 9 is connected.

In the antenna connector 1 configured as described above, when connecting an external antenna and a television receiver using the 75Ω coaxial cable 7, the line on the 75Ω output end 6 side of the balun 2 is mechanically cut, Above coaxial cable T
By the way, in the conventional antenna connector 1, -
If the external antenna and the television receiver are connected using the coaxial cable 7 with a resistance of 75Ω, the balun 2.
Since the line on the 75Ω output end 6 side of the balun 2 is cut, when connecting using the 300Ω ribbon feeder 3, the cut point on the 75Ω output end 6 side of the balun 2 must be soldered in order to match the impedance with the balun 2. etc., it becomes necessary to connect.

However, once the television receiver is in the hands of the first user, it is extremely difficult for the user to perform the connection work freely, so it is not possible to match the predetermined impedance. This results in the following problem. Also, when using a 75Ω coaxial cable 7,
The line on the 75Ω output end 6 side of the balun 2 is forgotten to be disconnected, and the impedance matching cannot be performed, which also causes a mistake.

Therefore, the present invention has a 75Ω input end and a 300Ωλ power end, and a 75Ω
In an antenna connector equipped with an Ω output end, the balun can be selectively used by operating a changeover switch depending on the impedance of the conducting wire used.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

The antenna connector constructed according to the present invention is constructed as shown in the equivalent circuit of FIG.
A 300Ω input end 24a is connected to the input side of a balun 21, which is a conversion transformer, to which conductive wires 23a and 23b of the ribbon feeder 22 having an internal resistance of 300Ω are respectively connected.

24b is provided, and the 75Ω output terminal 25 of the balun 21
On the side, there is a 75Ω input terminal 2 to which a coaxial cable 2T having an internal resistance of 75Ω is connected via a changeover switch 26.
8 is connected to a coaxial cable 29 having an internal resistance of 75Ω and having one end connected to an antenna terminal of a tuner in the television receiver 20. By the way, the changeover switch 26 has a first fixed contact 26a on the 75Ω output end 25 side of the balun 21, and a second fixed contact 26b on the 75Ω input end 28 side to which the coaxial cable 2T is connected. A movable contact 26c is provided on the connection end 27a side of the coaxial cable 2T connected to the image receiver.
When using a 300Ω ribbon feeder 22, one and the other conductive wires 23 of this ribbon feeder 22 are
a, 23b to the 300Ω input terminals 24a, 24b, and by switching the movable contact 26c of the changeover switch 26 to the first fixed contact 26a side, the balun 2
1, impedance matching is achieved and a connection is made between the external antenna and the television receiver. In addition, by connecting the coaxial cable 29 to the 75Ω input end 28 and switching the movable contact 26c of the changeover switch 26 to the second fixed contact 26b, impedance matching can be achieved without using the balance 21. The specific structure of the antenna connector according to the present invention, which is configured as the equivalent circuit shown in FIG. 2 described above and which connects an external antenna and a television receiver, will be described below. The antenna connector according to the present invention includes a case 30 formed by molding or the like of synthetic resin, which is an electrically insulating material. However, in this case 30, 3
One and the other conductive wires 23 of the 00Ω ribbon feeder 22
Screw 31a that clamps a and 23b.

Connecting terminal pieces 32a and 32b are provided in which the 75Ω coaxial cable 27 is screwed together, and alligator-shaped clamping pieces 33 and 34 are used to clamp and connect the shield wire 27b of the 75Ω coaxial cable 27 to hold the coaxial cable 2T. A grounding board 35 serving as a grounding portion is provided. An opening 36 is formed in the base 36 portion of the ground board 35, and a part of the case 30,
Alternatively, an insulating base 3γ, which is formed by bulging a part of the case 30, is faced. A connection pin 38 is provided so as to be inserted through the insulating base 3T, to which a core 129a of a 75Ω coaxial cable 29 connected to an antenna terminal of a tuner in the television receiver 20 is connected. One end of the connecting pin 38 is made to protrude into a cylindrical body part 39 into which the coaxial cable 29 protruding from one side of the case 30 is connected, as shown in FIG. . Note that a cylindrical connecting body 40 electrically connected to the grounding board 35 is disposed on the inner circumferential surface of the cylindrical body portion 39 .

The coaxial cable 29 connected to the antenna terminal of the tuner in the television receiver 20 is connected by inserting the connecting pin 38 into the core wire 29a and shielding M29b.
is fitted into and connected to the cylindrical body portion 39 so as to be connected to the cylindrical connecting body 40 .

As shown in FIG.
A switching tongue piece 41 is attached that constitutes a 75Ω input end 28 to which a core wire 27a of a 75Ω coaxial cable 27 connected to an external antenna is connected.

This switching tongue piece 41 is attached by inserting a cylindrical part 42 provided at the base end into the connecting pin 38, and is rotatable with respect to the connecting pin 38. The tip of the switching tongue piece 41 is bent into an arc shape, and a coaxial cable 27 is provided at the center of the tip.
A slotted hole 43 is provided through which the core wire 27a is inserted and connected.

Further, a fitting receiver 45 that becomes the first fixed contact 26a of the changeover switch 26 is installed on the insulating base 37 so as to face the changeover tongue piece 41.

The tip of the fitting receiver 45 is formed into a U-shape having a fitting groove 46 into which the tip of the switching tongue 41 can fit.

As shown in FIG. 3, the paran 21 is connected through 3 and the 75Ω output end 25 is connected to a part of the fitting receiver 45 by solder, and the ground end 21a is connected to the ground board 2.
5 is connected to a part of the case 30 by soldering and installed in the case 30.

In the antenna connector according to the present invention having the above-described structure, when using the 300Ω ribbon feeder 22, the switching tongue piece 41 is rotated to connect the fitting receiver 46.
3 by the action of the paran 21.
Connection between the external antenna and the television receiver is achieved by impedance matching between 00Ω and 75Ω.

In addition, at this time, the coaxial cable 2T provided in the fitting receiver 46
Since the slotted hole 43 to which the core wire 27a is connected is located in a position opposite to the insertion direction of the coaxial cable 2T, the coaxial cable 27 cannot be connected thereto.

In addition, when using a 75Ω coaxial cable 2T, rotate the switching tongue 41 to release the fitting to the fitting receiver 45 so that the slotted hole 43 is oriented in the insertion direction of the coaxial cable 27. , the core wire 27a is inserted through and connected to the slotted hole 43, and the shield wire 27b is connected to the clamping pieces 33, 34.
If they are held in place by holding the external antenna between them, the external antenna and the television receiver can be connected to each other by matching the impedance of 75Ω to 75Ω without being affected by the paran 21.

By the way, the changeover switch 26 consisting of the changeover tongue piece 41 and the fitting receiver 45 may be constructed as shown in FIG. 6. In the case shown in FIG. 6, the tip of the fitting receptacle 45 is
The switching tongue piece 4 is formed as a letter-shaped fitting groove part 46.
1 in the axial direction of the cylindrical portion 42 is attached to the connecting pin 38 via the cylindrical portion 42 so that it can slide freely in the vertical direction of the connecting pin 38 and can rotate freely with respect to the connecting pin 38. It is being

In addition, as shown in FIG. 7, the insulating substrate 3T of the fitting receiver 45
The insertion part 45a for the upper 2 insulating base 3T is made into a cylindrical shape.
It can be rotated freely. Then, the switching tongue piece 41 is fixed to the connecting pin 38, and a projecting piece 51 is provided on the cylindrical part 42 for attaching the switching tongue piece 41 to the connecting pin 38, and the projecting piece 51 and the fitting receiver 45 are moved relative to each other. The changeover switch 26 may be configured to engage. In addition,
In this example, the switching tongue piece 41 is a coaxial cable 2T.
It is attached to the connecting pin 3B in a state where it extends in the insertion direction.

According to the present invention as described above, it is possible to freely and selectively use a 300Ω ribbon feeder or a 75Ω coaxial cable by switching the changeover switch, and in particular, when using a coaxial cable, the output end of the balun can be used as desired, unlike conventional ones. Since there is no need to cut the side lines, it becomes possible to easily use the ribbon feeder again. It is especially effective when using either a ribbon feeder or a coaxial cable by changing the installation of the television receiver, and also provides two antenna connectors, one for the ribbon tweeter and one for the coaxial cable, to avoid misuse. There will be no need. Furthermore, the above-mentioned figures 5 and 6
In the case shown in the figure, since the disconnection of the switching tongue from the fitting receiving portion is related to the state in which the coaxial cable can be connected, it is possible to prevent misuse when using the coaxial cable.

[Brief explanation of drawings]

FIG. 1 is an equivalent circuit diagram showing a conventional example, FIG. 2 is an equivalent circuit diagram showing the present invention, FIG. 3 is a plan view showing the specific structure of the present invention, and FIG. FIG. 5 is a perspective view of the changeover switch portion; FIG.
The figure is a perspective view showing another embodiment of the changeover switch,
FIG. 7 is a perspective view showing still another embodiment of the changeover switch.

Claims (1)

[Claims] It has a 75Ω input end and a 300Ωλ power end, as well as a 75Ω
An antenna connector having an output end, wherein a changeover switch is provided between the output end and the pair of input ends to selectively switch between 75Ωλ power and 300Ω input.