JPH0119312B2 - - Google Patents
Info
- Publication number
- JPH0119312B2 JPH0119312B2 JP56067374A JP6737481A JPH0119312B2 JP H0119312 B2 JPH0119312 B2 JP H0119312B2 JP 56067374 A JP56067374 A JP 56067374A JP 6737481 A JP6737481 A JP 6737481A JP H0119312 B2 JPH0119312 B2 JP H0119312B2
- Authority
- JP
- Japan
- Prior art keywords
- transformer
- secondary winding
- input terminal
- winding
- circuit board
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/48—Networks for connecting several sources or loads, working on the same frequency or frequency band, to a common load or source
- H03H7/482—Networks for connecting several sources or loads, working on the same frequency or frequency band, to a common load or source particularly adapted for use in common antenna systems
Landscapes
- Details Of Television Systems (AREA)
- Structures For Mounting Electric Components On Printed Circuit Boards (AREA)
Description
【発明の詳細な説明】
本発明は１本のアンテナケーブルに複数台のテ
レビを接続できるようにしたテレビ共聴用分岐装
置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a branching device for common television viewing that allows a plurality of televisions to be connected to one antenna cable.
第１図は従来のテレビ共聴用分岐装置を示すも
のであり、同図に示すように従来の装置において
はフエライトコアなどを用いて形成される高周波
用のトランス４の１次巻線２の一端２ａを入力端
子５に接続し、他端２ｂを通過出力端子６に接続
し、トランス４の２次巻線３の一端３ａを接地
し、他端３ｂを抵抗７を介して入力端子５に接続
し、２次巻線３と抵抗７との接続点８から分岐出
力を取り出すようにしたものが一般に用いられて
おり、入力端子５にはテレビアンテナのアンテナ
ケーブルを接続し、分岐出力端子１２にテレビの
アンテナ端子を接続し、通過出力端子６には同じ
ような装置を何段も縦続接続して複数台のテレビ
に受信電波を供給できるようにしているものであ
る。しかるにこの種の装置においては、入力端子
５と通過出力端子６との間の損失、すなわち挿入
損が特に問題となり、この挿入損が大きいと分岐
装置を縦続に接続できる数が制限され、経済的な
差異を生ずるという問題があつた。 FIG. 1 shows a conventional TV common listening branching device. As shown in the figure, in the conventional device, the primary winding 2 of a high frequency transformer 4 formed using a ferrite core etc. One end 2a is connected to the input terminal 5, the other end 2b is connected to the passing output terminal 6, one end 3a of the secondary winding 3 of the transformer 4 is grounded, and the other end 3b is connected to the input terminal 5 via the resistor 7. Generally, a device is used in which the antenna cable of a television antenna is connected to the input terminal 5, and the branch output terminal 12 is connected to the input terminal 5. The antenna terminal of the television is connected to the terminal 6, and several stages of similar devices are connected in cascade to the pass-through output terminal 6, so that received radio waves can be supplied to a plurality of televisions. However, in this type of device, the loss between the input terminal 5 and the passing output terminal 6, that is, the insertion loss, is a particular problem.If the insertion loss is large, the number of branch devices that can be connected in cascade is limited, making it economically difficult. There was a problem that it caused a huge difference.
本発明は上述のような点に鑑みて為されたもの
であり、分岐に用いられる中空円筒状のフエライ
ト製トランスの実装方法を工夫することにより、
挿入損を小さくして多数のテレビを接続できるよ
うにしたテレビ共聴用分岐装置を提供することを
目的とするものである。 The present invention has been made in view of the above points, and by devising a mounting method for a hollow cylindrical ferrite transformer used for branching,
It is an object of the present invention to provide a branching device for television shared viewing that can connect a large number of televisions with a reduced insertion loss.
以下本発明の構成を図示実施例について説明す
ると、第２図乃至第５図に示すように中空円筒状
のフエライトコア１に軸方向と平行な１次巻線２
および２次巻線３を巻装してトランス４を形成
し、トランス４の１次巻線２の一端２ａを入力端
子５に接続し、他端２ｂを通過出力端子６に接続
し、トランス４の２次巻線３の一端３ａを接地
し、他端３ｂを抵抗７を介して入力端子５に接続
し、２次巻線３と抵抗７との接続点８から分岐出
力を取り出すようにしたテレビ共聴用分岐装置に
おいて、回路実装用のプリント基板９に前記円筒
状のトランス４の側面を密接させて実装すると共
に、１次巻線と２次巻線をプリント基板の面に対
して平行で、かつプリント基板に近接する面内で
フエライトコアに巻装したものである。分岐出力
は第２図ａ，ｂの実施例に示すように２次巻線３
と抵抗７との接続点８から直接的に取り出しても
かまわないが、第３図の実施例に示すように整合
用トランス１０を介して取り出すようにすれば分
岐出力レベルが向上すると共に、分岐出力
VSWR（電圧定在波比）が良好となるものであ
る。ここで第２図ａに示す回路についてその動作
を説明すると、同図ａに示すように入力側に信号
源１１が接続されているときには入力端子５から
流入した電流は通過出力端子６に流れる電流I1
と、分岐出力端子１２に流れる電流I2とになる。
このうち電流I1は１：ｎの巻数比を持つトランス
４の１次巻線２を流れるのでトランス４の２次巻
線３には電流I3が第２図ａの１点鎖線に示すよう
に流れるものである。この結果分岐出力端子１２
には（I2＋I3）R0の電圧が誘起される。この電圧
が分岐出力端子１２に接続されたテレビの入力信
号レベルとなるものである。この入力信号レベル
は、入力側に接続した信号源１１の電圧レベルＥ
の1/3乃至1/4になるようにトランス４の巻数比
１：ｎと抵孔R1の値が選定されている。また入
力端子５に接続した信号源１１の電力は、大部分
は通過出力端子６にロスなく伝送されるものであ
り、後段のテレビ共聴用分岐装置において順次入
力信号として処理されるものである。次に第２図
ｂに示すように分岐出力端子１２の側に、例えば
局部発振器のような信号源１１が接続されている
場合には、分岐出力端子１２から流入する電流は
２次巻線３を介してアースに流れる電流I1と、抵
抗R1を介して入力端子５に流れる電流I2と、通過
出力端子６に流れる電流I3とになるものである。
このうち電流I1はトランス４の２次側を流れるの
で、トランス４の１次側には第２図ｂの１点鎖線
に示すような電流I4が流れるものである。ところ
で同図ｂに示すように入力端子５においては電流
I2とI4とは加算され、通過出力端子６においては
電流I3とI4とは減算される。この結果分岐出力端
子１２に接続された信号源１１の出力の一部は入
力端子５の側に伝達されるが、通過出力端子６の
側にはほとんど伝達されないことになる。このこ
とは分岐出力端子１２と通過出力端子６とにそれ
ぞれテレビが接続されている場合に、各テレビか
ら発生する電波ノイズによるテレビ間の相互干渉
が極めて小さくなることを意味するものである。 The structure of the present invention will be described below with reference to the illustrated embodiment. As shown in FIGS. 2 to 5, a hollow cylindrical ferrite core 1 has a primary winding 2 parallel to the axial direction.
and a secondary winding 3 to form a transformer 4, one end 2a of the primary winding 2 of the transformer 4 is connected to the input terminal 5, the other end 2b is connected to the pass output terminal 6, and the transformer 4 One end 3a of the secondary winding 3 is grounded, the other end 3b is connected to the input terminal 5 via the resistor 7, and a branched output is taken out from the connection point 8 between the secondary winding 3 and the resistor 7. In a branching device for television public viewing, the cylindrical transformer 4 is mounted on a printed circuit board 9 with the side surfaces of the cylindrical transformer 4 in close contact with each other, and the primary and secondary windings are mounted parallel to the surface of the printed circuit board. and is wound around a ferrite core in the plane close to the printed circuit board. The branch output is connected to the secondary winding 3 as shown in the embodiments of Fig. 2a and b.
It may be taken out directly from the connection point 8 between the and the resistor 7, but if the output is taken out through a matching transformer 10 as shown in the embodiment shown in FIG. 3, the branch output level will be improved and the branch output
This provides good VSWR (voltage standing wave ratio). Now, to explain the operation of the circuit shown in FIG. 2A, when the signal source 11 is connected to the input side as shown in FIG. I 1
, the current I 2 flows through the branch output terminal 12.
Of these, current I 1 flows through the primary winding 2 of the transformer 4 which has a turns ratio of 1:n, so the current I 3 flows through the secondary winding 3 of the transformer 4 as shown by the dashed line in Figure 2a. It is something that flows. As a result, branch output terminal 12
A voltage of (I 2 + I 3 ) R 0 is induced in . This voltage becomes the input signal level of the television connected to the branch output terminal 12. This input signal level is the voltage level E of the signal source 11 connected to the input side.
The turns ratio of the transformer 4 (1:n) and the value of the resistor R 1 are selected so that the ratio is 1/3 to 1/4 of . Furthermore, most of the power from the signal source 11 connected to the input terminal 5 is transmitted to the pass-through output terminal 6 without loss, and is sequentially processed as an input signal in the TV shared viewing branching device at the subsequent stage. . Next, if a signal source 11 such as a local oscillator is connected to the branch output terminal 12 as shown in FIG. A current I 1 flows to the ground via the resistor R 1 , a current I 2 flows to the input terminal 5 via the resistor R 1 , and a current I 3 flows to the passing output terminal 6 .
Since the current I 1 flows through the secondary side of the transformer 4, a current I 4 as shown by the dashed line in FIG. 2B flows through the primary side of the transformer 4. By the way, as shown in figure b, the current at input terminal 5 is
I 2 and I 4 are added, and at the pass-through output terminal 6 currents I 3 and I 4 are subtracted. As a result, a part of the output of the signal source 11 connected to the branch output terminal 12 is transmitted to the input terminal 5 side, but almost no output is transmitted to the passing output terminal 6 side. This means that when televisions are connected to the branch output terminal 12 and the passing output terminal 6, mutual interference between the televisions due to radio noise generated from each television is extremely small.
次に第４図は回路実装用のプリント基板９への
トランス４の実装方法を示すものであり、同図ａ
は本発明による正しい実装方法、同図ｂはこれと
比較するための対比実験に用いた間違つた実装方
法を示している。第５図は第４図ａ，ｂに示すそ
れぞれの場合について使用周波数〔ＭHz〕に対
する挿入損Liを示すものである。同図中90MHz乃
至230MHzの範囲はVHF帯を示しており、また
470MHz乃至770MHzの範囲はUHF帯に対応する
ものである。これらの周波数を取り扱うトランス
４の１次巻線２および２次巻線３を第４図ａに示
すように回路実装用のプリント基板９の面に対し
て平行で、かつプリント基板９に近接する面内で
フエライトコア１に巻装した場合には第５図のＡ
に示すように挿入損Liが小さいが、第４図ｂに示
すように１次巻線２および２次巻線３をプリント
基板９の面に対して垂直な面内でフエライトコア
１に巻装（なお、この場合にはいずれかの巻線
２，３がプリント基板９から離される。）した場
合には第５図のＢに示すように挿入損Liが全周波
数範囲に亘つて一様に大きくなる。このような差
異が生じた原因としては、１次巻線２と２次巻線
３との間の磁束の結合度の若干の差異と、プリン
ト基板９をグランド面としたときの１次巻線２と
２次巻線３のグランドに対する特性インピーダン
スの差異によるものと思われ、特に後者の影響が
大きいと考えられる。 Next, Fig. 4 shows a method of mounting the transformer 4 on the printed circuit board 9 for circuit mounting.
1 shows the correct mounting method according to the present invention, and FIG. FIG. 5 shows the insertion loss Li with respect to the operating frequency [MHz] for each case shown in FIGS. 4a and 4b. The range from 90MHz to 230MHz in the figure indicates the VHF band, and
The range from 470MHz to 770MHz corresponds to the UHF band. The primary winding 2 and secondary winding 3 of the transformer 4 that handles these frequencies are parallel to and close to the surface of the printed circuit board 9 for circuit mounting, as shown in FIG. 4a. When the ferrite core 1 is wound in-plane, A in Fig. 5
Although the insertion loss Li is small as shown in FIG. (In this case, one of the windings 2 and 3 is separated from the printed circuit board 9.) In this case, the insertion loss Li is uniform over the entire frequency range as shown in B in Fig. 5. growing. The causes of such a difference include a slight difference in the degree of magnetic flux coupling between the primary winding 2 and the secondary winding 3, and a difference in the degree of coupling of the primary winding when the printed circuit board 9 is used as the ground plane. This is thought to be due to the difference in characteristic impedance with respect to ground between the secondary winding 2 and the secondary winding 3, and the latter is thought to have a particularly large influence.
本発明は以上のように中空円筒状のフエライト
コアに軸方向と平行に１次巻線及び２次巻線を巻
装してトランスを形成し、トランスの１次巻線の
一端を入力端子に接続し、他端を通過出力端子に
接続し、トランスの２次巻線の一端を接地し、他
端を抵抗を介して入力端子に接続し、２次巻線と
抵抗との接続点から分岐出力を取り出すようにし
たテレビ共聴用分岐装置において、回路実装用の
プリント基板に前記円筒状トランスの側面を密接
させて実装すると共に、１次巻線と２次巻線をプ
リント基板の面に対して平行で、かつプリント基
板に近接する面内でフエライトコアに巻装したも
のであり、その挿入損を他の実装方法を用いた分
岐装置と比較すると、全周波数帯に亘つて挿入損
が小さくなつており、したがつて本発明の装置を
用いれば分岐装置を従来よりも多数縦続接続する
ことができ、１つのアンテナを用いて受信できる
テレビの数を多くすることができるという利点を
有するものである。しかも、トランスを実装する
方法を変えるだけであるから、コストの上昇や装
置の大型化を招くことがない。また、回路実装用
のプリント基板に前記円筒状トランスの側面を密
接させれば、トランスを安定してプリント基板上
に取り付けることができ、たとえばトランスを立
てて取り付けた場合のように、トランスが振動な
どで傾いたりすることがなく、機械的に安定した
取付が可能となつて、特性のばらつきも少なくな
り、結果的に性能の安定したテレビ共聴用分岐装
置を容易に製造できるという利点も有する。 As described above, the present invention forms a transformer by winding a primary winding and a secondary winding around a hollow cylindrical ferrite core parallel to the axial direction, and connects one end of the primary winding of the transformer to an input terminal. Connect the other end to the passing output terminal, ground one end of the secondary winding of the transformer, connect the other end to the input terminal via the resistor, and branch from the connection point between the secondary winding and the resistor. In a branching device for television public listening in which output is taken out, the cylindrical transformer is mounted on a printed circuit board for circuit mounting with the side surface of the cylindrical transformer in close contact with the other, and the primary winding and secondary winding are mounted on the surface of the printed board. It is wrapped around a ferrite core in a plane parallel to the PCB and close to the printed circuit board, and when comparing its insertion loss with branching devices using other mounting methods, the insertion loss is lower over the entire frequency band. Therefore, the device of the present invention has the advantage that a greater number of branching devices can be connected in cascade than before, and the number of televisions that can be received using one antenna can be increased. It is something. Furthermore, since the method of mounting the transformer is simply changed, there is no increase in cost or increase in the size of the device. In addition, if the side surface of the cylindrical transformer is brought close to the printed circuit board for circuit mounting, the transformer can be stably mounted on the printed circuit board. It also has the advantage that it can be installed mechanically without tilting or tilting, and that there is less variation in characteristics, and as a result, it is easy to manufacture a branching device for TV shared viewing with stable performance. .
第１図は従来の分岐装置の回路図、第２図ａ，
ｂは本発明の一実施例の回路図、第３図は同上の
他の実施例の回路図、第４図ａは本発明の分岐装
置におけるトランス部の斜視図、同図ｂは同上と
対比するために示した他の分岐装置におけるトラ
ンス部の斜視図、第５図は第４図ａ，ｂに示す分
岐装置の特性図である。
１はフエライトコア、２は１次巻線、３は２次
巻線、４はトランス、５は入力端子、６は通過出
力端子、７は抵抗、９はプリント基板、１２は分
岐出力端子である。
Figure 1 is a circuit diagram of a conventional branching device, Figure 2a,
FIG. 4b is a circuit diagram of an embodiment of the present invention, FIG. 3 is a circuit diagram of another embodiment of the same as above, FIG. 4a is a perspective view of a transformer section in a branching device of the present invention, and FIG. FIG. 5 is a perspective view of a transformer section in another branching device shown for the purpose of the present invention, and FIG. 5 is a characteristic diagram of the branching device shown in FIGS. 4a and 4b. 1 is a ferrite core, 2 is a primary winding, 3 is a secondary winding, 4 is a transformer, 5 is an input terminal, 6 is a passing output terminal, 7 is a resistor, 9 is a printed circuit board, 12 is a branch output terminal .
Claims (1)
に１次巻線及び２次巻線を巻装してトランスを形
成し、トランスの１次巻線の一端を入力端子に接
続し、他端を通過出力端子に接続し、トランスの
２次巻線の一端を接地し、他端を抵抗を介して入
力端子に接続し、２次巻線と抵抗との接続点から
分岐出力を取り出すようにしたテレビ共聴用分岐
装置において、回路実装用のプリント基板に前記
円筒状トランスの側面を密接させて実装すると共
に、１次巻線と２次巻線をプリント基板の面に対
して平行で、かつプリント基板に近接する面内で
フエライトコアに巻装して成ることを特徴とする
テレビ共聴用分岐装置。1 A transformer is formed by winding a primary winding and a secondary winding around a hollow cylindrical ferrite core parallel to the axial direction, and one end of the primary winding of the transformer is connected to an input terminal, and the other end is connected to an input terminal. Connected to the pass output terminal, grounded one end of the secondary winding of the transformer, connected the other end to the input terminal via a resistor, and took out the branch output from the connection point between the secondary winding and the resistor. In a branching device for television public listening, the cylindrical transformer is mounted on a printed circuit board for circuit mounting with the side surface of the cylindrical transformer in close contact, and the primary winding and the secondary winding are parallel to the surface of the printed board, and A branching device for common television viewing, characterized in that it is wound around a ferrite core in a plane close to a printed circuit board.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56067374A JPS57183183A (en) | 1981-05-01 | 1981-05-01 | Branching device for community tv reception |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56067374A JPS57183183A (en) | 1981-05-01 | 1981-05-01 | Branching device for community tv reception |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57183183A JPS57183183A (en) | 1982-11-11 |
| JPH0119312B2 true JPH0119312B2 (en) | 1989-04-11 |
Family
ID=13343165
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56067374A Granted JPS57183183A (en) | 1981-05-01 | 1981-05-01 | Branching device for community tv reception |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57183183A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4768337B2 (en) * | 2005-07-05 | 2011-09-07 | ゼブラ株式会社 | Double-headed padding writing instrument |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA868033A (en) * | 1969-11-07 | 1971-04-06 | Lindsay Specialty Products Limited | Directional communication signal tap |
| JPS4814738U (en) * | 1971-07-02 | 1973-02-19 | ||
| JPS5366345A (en) * | 1977-11-16 | 1978-06-13 | Maspro Denko Kk | Television community receiving distributor circuit |
-
1981
- 1981-05-01 JP JP56067374A patent/JPS57183183A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57183183A (en) | 1982-11-11 |
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