JPS6348453B2 - - Google Patents
Info
- Publication number
- JPS6348453B2 JPS6348453B2 JP56106367A JP10636781A JPS6348453B2 JP S6348453 B2 JPS6348453 B2 JP S6348453B2 JP 56106367 A JP56106367 A JP 56106367A JP 10636781 A JP10636781 A JP 10636781A JP S6348453 B2 JPS6348453 B2 JP S6348453B2
- Authority
- JP
- Japan
- Prior art keywords
- switch
- preset
- circuit
- channel
- switching
- 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
- 230000007547 defect Effects 0.000 claims description 6
- 108091006146 Channels Proteins 0.000 description 37
- 230000010355 oscillation Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
- H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
- H03J7/02—Automatic frequency control
Landscapes
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
Description
【発明の詳細な説明】
本発明はテレビジヨン受像機等の選局回路に関
するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a channel selection circuit for a television receiver or the like.
斯種選局回路ではチヤンネル切換え時にAFT
（自動微細同調）を不作動とするためAFTデイフ
イート回路を駆動する信号をチヤンネル切換えに
応じて得ることが行なわれるが、本発明はこのよ
うな信号を極めて好適に取り出しうるようにした
選局回路を提案するものである。 This type of channel selection circuit uses AFT when switching channels.
In order to disable automatic fine tuning, a signal to drive the AFT defect circuit is obtained in response to channel switching, but the present invention provides a tuning circuit that can extract such a signal very suitably. This is what we propose.
以下図面に示した実施例に従つて説明する。 The following will explain the embodiments shown in the drawings.
図において、１はチユーナであつて同調電圧入
力端子Tu、VHFの帯域切換え用電圧入力端子
Ｓ、UHF動作電圧入力端子UB、VHF動作電圧入
力端子VBを有している。２はAFT電圧形成回路
であり、チユーナ１のIF出力をVIF回路（図示せ
ず）を経て受信し例えば映像IFキヤリアの周波
数ずれに応じた出力を発生し、この出力によつて
チユーナの局部発振周波数を自動制御する。前記
AFT回路２の出力は端子３，４間が短絡される
と無効になる。５は入力端子６にハイレベルが印
加されると、前記端子３，４短絡するように働く
AFTデイフイート回路である。SW1，SW2…
SW3は各チヤンネルごとに設けられた選局スイツ
チであり、互いに連動する第１スイツチａと第２
スイツチｂとよりなると共に、１つのチヤンネル
の選局スイツチがオンしたときに他のチヤンネル
の選局スイツチはオフになるように構成されてい
るものとする。各チヤンネルの第１スイツチａの
一端は同調電圧設定用のポテンシヨメータP1，
P2…Pnの可変端子に接続され、他端はチユーナ
１の同調電圧入力端子Tuに結合されている。ポ
テンシヨメータP1，P2…Pnはいずれも＋30Vの
電源とアース間に挿入された態様となつている。
第２スイツチｂの一端はチヤンネル表示用の発光
ダイオードD1，D2…Dnのカソード側に接続さ
れ、他端はアースに結合されている。＋15Vの電
源ライン７に対し３ケの抵抗R1，R2，R3が接続
されているが、この抵抗R1，R2，R3の他端には
帯域切換え用のプリセツトスイツチBS1，BS2…
BSnの３つの接点VL，VH，Ｕがそれぞれ接続さ
れていて、そのうちのUHFバンド用接点Ｕは抵
抗R1に、ハイバンド用接点VHは抵抗R2に、そし
てローバンド用接点VLは抵抗R3に接続されてい
る。各プリセツトスイツチBS1，BS2…BSnの可
動片は上記チヤンネル表示用発光ダイオードD1，
D2…Dnのアノードに接続されている。前記プリ
セツトスイツチのローバンド接点VLは同時にト
ランジスタQ3のベースにブリーダ抵抗R8，R9を
介して結合されており、一方UHFバンド用接点
Ｕは抵抗R5を介してトランジスタQ1のベースに
接続されている。尚、R4はバイアス抵抗である。
前記トランジスタQ3のエミツタはアースされて
いるが、コレクタは抵抗R11を介して電源（＋
30V）に接続されると共に直接チユーナ１の帯域
切換え電圧入力端子Ｓに接続されている。上記ト
ランジスタQ1の出力はコレクタから直接チユー
ナ１の端子UBに与えられると共に抵抗R10，R7を
介してトランジスタQ2のベースにも与えられる。
トランジスタQ2の出力はコレクタからチユーナ
の端子VBに供給される。チユーナ１はローバン
ド受信時には端子Ｓに＋30V、端子VBに＋15Vが
与えられ、ハイバンド受信時にVBに＋15V、Ｓ
に0Vが与えられる。またUHF受信時にはVB，Ｓ
は0V、UBに＋15Vが与えられなければならない。
前記トランジスタQ1，Q2，Q3からなる帯域切換
え回路８及び第２スイツチｂは選局動作に応じて
１つのプリセツトスイツチのプリセツト内容を他
のプリセツトスイツチのプリセツト内容に切換え
てチユーナ１に作用せしめる第１手段９を形成す
る。１０は前記プリセツト内容の切換えの際に前
記いずれかの抵抗に生ずる両端電圧の過渡変化を
利用してAFTデイフイート回路６駆動用信号を
得る第２手段であつて、該第２手段は前記抵抗
R1，R2，R3にそれぞれカソードが接続されスイ
ツチングダイオードd1，d2，d3と前記＋15Vの電
源ライン７と前記スイツチングダイオードd1，
d2，d3のアノードに共通接続された第２の抵抗
R0とから成り、その出力は接続点イから得られ
る。 In the figure, 1 is a tuner having a tuning voltage input terminal Tu, a VHF band switching voltage input terminal S, a UHF operating voltage input terminal UB , and a VHF operating voltage input terminal VB . 2 is an AFT voltage forming circuit which receives the IF output of tuner 1 via a VIF circuit (not shown) and generates an output according to the frequency deviation of the video IF carrier, for example, and uses this output to generate the tuner's local oscillation. Automatically control frequency. Said
The output of the AFT circuit 2 becomes invalid when terminals 3 and 4 are short-circuited. 5 acts to short-circuit the terminals 3 and 4 when a high level is applied to the input terminal 6.
It is an AFT dayfeet circuit. SW1 , SW2 ...
SW 3 is a tuning switch provided for each channel, and the first switch a and the second switch are interlocked with each other.
It is assumed that the channel selection switch b consists of a switch b, and that when the channel selection switch of one channel is turned on, the channel selection switches of other channels are turned off. One end of the first switch a of each channel is a potentiometer P 1 for setting the tuning voltage,
P2 ... is connected to the variable terminal of Pn, and the other end is coupled to the tuning voltage input terminal Tu of the tuner 1. The potentiometers P 1 , P 2 . . . Pn are all inserted between the +30V power supply and ground.
One end of the second switch b is connected to the cathode side of the channel display light emitting diodes D 1 , D 2 . . . Dn, and the other end is connected to ground. Three resistors R 1 , R 2 , R 3 are connected to the +15V power supply line 7, and the other end of these resistors R 1 , R 2 , R 3 is a preset switch BS 1 for band switching. ,BS 2 …
Three contacts V L , V H , and U of BSn are connected respectively, among which the UHF band contact U is connected to the resistor R 1 , the high band contact V H is connected to the resistor R 2 , and the low band contact V L is connected to resistor R3 . The movable pieces of each preset switch BS 1 , BS 2 ...BSn are the channel display light emitting diodes D 1 ,
D 2 ...Connected to the anode of Dn. The low band contact V L of the preset switch is simultaneously coupled to the base of transistor Q 3 via bleeder resistors R 8 and R 9 , while the UHF band contact U is coupled to the base of transistor Q 1 via resistor R 5 . It is connected to the. Note that R4 is a bias resistance.
The emitter of the transistor Q3 is grounded, but the collector is connected to the power supply (+
30V) and directly connected to the band switching voltage input terminal S of the tuner 1. The output of the transistor Q 1 is applied directly from the collector to the terminal U B of the tuner 1 and also to the base of the transistor Q 2 via resistors R 10 and R 7 .
The output of transistor Q 2 is supplied from the collector to terminal V B of the tuner. Tuner 1 receives +30V to terminal S and +15V to terminal VB when receiving low band, and +15V to VB and +15V to terminal VB when receiving high band.
0V is given to Also, when receiving UHF, V B , S
must be given 0V, and +15V must be given to U B.
The band switching circuit 8 consisting of the transistors Q 1 , Q 2 , and Q 3 and the second switch b switch the preset contents of one preset switch to the preset contents of another preset switch according to the tuning operation, and switch the tuner 1 to the preset contents of the other preset switch. A first means 9 is formed to act on the first means 9. Reference numeral 10 denotes a second means for obtaining a signal for driving the AFT defect circuit 6 by utilizing a transient change in the voltage across one of the resistors when the preset contents are changed;
The cathodes are connected to R 1 , R 2 , R 3 respectively, and the switching diodes d 1 , d 2 , d 3 and the +15V power supply line 7 and the switching diode d 1 ,
A second resistor commonly connected to the anodes of d 2 and d 3
R 0 and its output is obtained from connection point A.
次に動作について説明する。 Next, the operation will be explained.
今、第１チヤンネル以外の任意のチヤンネルが
受信されている状態から第１チヤンネルの受信状
態に切換える場合について説明する。第１チヤン
ネルに切換える前の状態ではラインl1，l2，l3の
いずれか１つがローレベルになつているので、ス
イツチングダイオードd1，d2，d3のいずれか１つ
がオンしてイ点からはローレベル（2.5V）が出
力されるだけであり、AFTデイフイート回路５
は動作せず、従つてAFT回路２の端子３，４は
短絡されないのでAFT回路２で形成されたAFT
電圧は無効にされることなくチユーナ１の局部発
振回路に有効に作用している。 Now, a case will be described in which a state in which any channel other than the first channel is being received is switched to a receiving state in which the first channel is received. Before switching to the first channel, one of the lines l 1 , l 2 , and l 3 is at low level, so one of the switching diodes d 1 , d 2 , and d 3 is turned on. Only a low level (2.5V) is output from point A, and the AFT defect circuit 5
does not operate, and therefore terminals 3 and 4 of AFT circuit 2 are not shorted, so the AFT formed by AFT circuit 2
The voltage is effectively acting on the local oscillation circuit of the tuner 1 without being nullified.
第１チヤンネルに切換えるべく選局スイツチ
SW1をオンすると、今まで受信状態にあつたチヤ
ンネルの選局スイツチは開くので、そのチヤンネ
ルのプリセツトスイツチと発光ダイオードを通し
てアースに接続された状態は断たれる。しかも第
１チヤンネルの選局スイツチSW1を操作して完全
にオンするまでの間に前記受信状態にあつたチヤ
ンネルの選局スイツチはオフになるので、第１チ
ヤンネルの受信切換えが達成されるまでに短時間
ではあるが、いずれの選局スイツチSW1，SW2…
SWnもオフになる時間が存在することになる。
このため、その時間内では抵抗R1，R2，R3の電
圧降下は生じず、従つてラインl1，l2，l3はいず
れも＋15Vになり、スイツチングダイオードd1，
d2，d3は全てオフになると共にイ点の電位も＋
15Vに上がる。第１チヤンネルの選局スイツチ
SW1が完全にオンになると、抵抗R3→プリセツ
トスイツチBS1→発光ダイオードD1→第２スイツ
チｂ→アースの経路で電流が流れラインl3の電位
はローレベルとなるのでスイツチングダイオード
d3がオンしてイ点は＋2.5Vに下がる。従つてチ
ヤンネル切換えの際に第２手段１０からはＡの如
きパルスが生じ、その正パルス期間又はその期間
に対応する一定時間だけAFTデイフイート回路
５が働らき、AFT回路２で形成されたAFT電圧
をチユーナに作用させない。第１チヤンネルの選
局スイツチSW1が完全にオンになると、ポテンシ
ヨメータP1で設定された同調電圧が第１スイツ
チａを通してチユーナ１の端子Tuに印加される。 Turn the selection switch to switch to the first channel.
When SW 1 is turned on, the tuning switch of the channel that has been in the reception state is opened, so the connection to ground through the preset switch and light emitting diode of that channel is cut off. In addition, the tuning switch of the channel that was in the reception state will be turned off before the tuning switch SW 1 of the first channel is operated and turned on completely, so the switching of the reception of the first channel will be completed. For a short time, either channel selection switch SW 1 , SW 2 ...
There is also a time when SWn is turned off.
Therefore, no voltage drop occurs across the resistors R 1 , R 2 , and R 3 during that time, so lines l 1 , l 2 , and l 3 all become +15V, and the switching diodes d 1 ,
d 2 and d 3 are all turned off, and the potential at point A also becomes +
Increases to 15V. Channel 1 selection switch
When SW 1 is completely turned on, current flows through the path of resistor R 3 → preset switch BS 1 → light emitting diode D 1 → second switch b → ground, and the potential of line l 3 becomes low level, so the switching diode
d3 turns on and the A point drops to +2.5V. Therefore, when switching channels, a pulse such as A is generated from the second means 10, and the AFT defect circuit 5 operates for a period of the positive pulse or a certain period corresponding to the period, and the AFT voltage formed by the AFT circuit 2 is does not affect Chuyuna. When the tuning switch SW 1 of the first channel is completely turned on, the tuning voltage set by the potentiometer P 1 is applied to the terminal Tu of the tuner 1 through the first switch a.
第１チヤンネルのプリセツトスイツチSW1はロ
ーバンドに設定されているので、第１チヤンネル
の選局によりトランジスタQ3のベースはローレ
ベルとなり、該トランジスタQ3がオフとなつて
チユーナ１の端子Ｓには＋30Vが与えられチユー
ナ１の内部同調回路はローバンドに設定される。
また、ラインl1はハイレベル（＋15V）であるか
ら、トランジスタQ1はオフとなる。抵抗R10は比
較的小さい値（1KΩ以下）であり、トランジス
タQ1のオフ時にロ点に生じる電圧は低く端子UB
にはUHF駆動電圧は与えられない。一方、ハ点
も低くなることによりトランジスタQ2がオンし
て端子VBにはVHF駆動電圧が与えられる。前記
抵抗R10はチユーナ１の端子Ｓから内部をみたイ
ンピーダンスによつて代用することも可能であ
る。 Since the preset switch SW 1 of the first channel is set to the low band, the base of the transistor Q 3 goes to a low level due to the selection of the first channel, and the transistor Q 3 is turned off, and the terminal S of the tuner 1 is connected to the base of the transistor Q 3 . +30V is applied to tuner 1, and the internal tuning circuit of tuner 1 is set to low band.
Also, since the line l1 is at a high level (+15V), the transistor Q1 is turned off. Resistor R 10 has a relatively small value (1KΩ or less), and the voltage generated at point R when transistor Q 1 is turned off is low at terminal U B
No UHF drive voltage is provided. On the other hand, since the point C also becomes low, the transistor Q2 is turned on and the VHF drive voltage is applied to the terminal VB . The resistor R 10 can also be replaced by an impedance viewed from the terminal S of the tuner 1 inside.
以上説明したように本発明によればチヤンネル
切換え時のAFTデイフイート回路駆動用の信号
を選局回路から極めて好適に取り出すことができ
有効である。 As explained above, according to the present invention, the signal for driving the AFT defect circuit at the time of channel switching can be very suitably extracted from the channel selection circuit, which is effective.
また本発明によれば電源に対し複数の抵抗を接
続すると共に、この抵抗の他端に受信帯域プリセ
ツトスイツチと帯域切換え回路を接続し、前記プ
リセツトスイツチの他端と基準電位点間にチヤン
ネル表示用発光ダイオードと選局動作に応じて動
作するスイツチの直列回路を接続しているので、
チヤンネル表示用発光ダイオード駆動用スイツチ
とバンド切換え回路駆動スイツチとが選局スイツ
チSW1，SW2…SWnの第２スイツチｂで兼用さ
れる形となり、第１スイツチａは同調用のみに使
用できる。従つて、もし第１スイツチａ側を同調
電圧抽出駆動用と帯域切換え回路駆動用とした場
合には各チヤンネルに同調電圧側と帯域切換え側
の相互影響を阻止するダイオードを必要とする
が、本発明ではそのようなダイオードは不要とな
る。 Further, according to the present invention, a plurality of resistors are connected to the power supply, and a receiving band preset switch and a band switching circuit are connected to the other end of the resistor, and a channel is connected between the other end of the preset switch and a reference potential point. Since the display light emitting diode is connected to a series circuit of a switch that operates according to the channel selection operation,
The second switch b of the channel selection switches SW1 , SW2 , . Therefore, if the first switch a side is used for tuning voltage extraction driving and band switching circuit driving, a diode is required for each channel to prevent mutual influence between the tuning voltage side and the band switching side. The invention eliminates the need for such diodes.
図面は本発明を実施した選局回路の回路図であ
る。
１……チユーナ、２……AFT回路、５……
AFTデイフイート回路、７……＋15V電源ライ
ン、９……第１手段、１０……第２手段、R1，
R2，R3……抵抗、SW1，SW2，SWn……選局ス
イツチ、BS1，BS2，BSn……受信帯域プリセツ
トスイツチ、d1，d2，d3……スイツチングダイオ
ード、D1，D2，D3……チヤンネル表示用発光ダ
イオード、R0……第２の抵抗。
The drawing is a circuit diagram of a channel selection circuit embodying the present invention. 1... Chuyuna, 2... AFT circuit, 5...
AFT daylight circuit, 7... +15V power supply line, 9... first means, 10... second means, R 1 ,
R 2 , R 3 ... Resistor, SW 1 , SW 2 , SWn ... Tuning switch, BS 1 , BS 2 , BSn ... Reception band preset switch, d 1 , d 2 , d 3 ... Switching diode , D 1 , D 2 , D 3 ... Channel display light emitting diode, R 0 ... Second resistor.
Claims (1)
端に複数の受信帯域プリセツトスイツチと帯域切
換え回路を接続し、選局動作に応じて１つの受信
帯域プリセツトスイツチのプリセツト内容を他の
受信帯域プリセツトスイツチのプリセツト内容に
切換えてチユーナに作用せしめると共に、複数の
前記受信帯域プリセツトスイツチの他端と基準電
位点間に前記選局動作に応じて動作する第２スイ
ツチとチヤンネル表示用発光ダイオードとの直列
回路を接続してなる選局回路に於いて、 前記抵抗と前記受信帯域プリセツトスイツチの
各接続点に一端が接続された複数のスイツチング
ダイオードと、 一端が前記電源に接続され、他端が前記スイツ
チングダイオードの他端に接続され、この他端よ
りAFTデイフイート回路駆動信号を出力する第
２の抵抗と、 前記第２スイツチと連動し前記チユーナに同調
電圧を出力する第１スイツチとを、 備えることを特徴とする選局回路。[Claims] 1. A plurality of resistors are connected to a power source, and a plurality of reception band preset switches and a band switching circuit are connected to the other ends of the resistors, and one reception band preset switch is selected according to a channel selection operation. The preset content of the preset switch is switched to the preset content of the other reception band preset switch to act on the tuner, and a switch that operates in accordance with the tuning operation is connected between the other ends of the plurality of reception band preset switches and the reference potential point. A plurality of switching diodes each having one end connected to each connection point between the resistor and the receiving band preset switch; a second resistor, one end of which is connected to the power supply, the other end of which is connected to the other end of the switching diode, and outputs an AFT defect circuit drive signal from the other end; A tuning circuit comprising: a first switch that outputs a tuning voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10636781A JPS587916A (en) | 1981-07-07 | 1981-07-07 | Channel selecting circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10636781A JPS587916A (en) | 1981-07-07 | 1981-07-07 | Channel selecting circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS587916A JPS587916A (en) | 1983-01-17 |
| JPS6348453B2 true JPS6348453B2 (en) | 1988-09-29 |
Family
ID=14431748
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10636781A Granted JPS587916A (en) | 1981-07-07 | 1981-07-07 | Channel selecting circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS587916A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0718276Y2 (en) * | 1989-08-22 | 1995-05-01 | タキロン株式会社 | Agricultural horticultural support |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5840936U (en) * | 1981-09-09 | 1983-03-17 | 三洋電機株式会社 | Tuning circuit |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS562649B2 (en) * | 1973-04-25 | 1981-01-21 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS599454Y2 (en) * | 1979-06-20 | 1984-03-26 | 松下電器産業株式会社 | Channel selection device |
-
1981
- 1981-07-07 JP JP10636781A patent/JPS587916A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS562649B2 (en) * | 1973-04-25 | 1981-01-21 |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0718276Y2 (en) * | 1989-08-22 | 1995-05-01 | タキロン株式会社 | Agricultural horticultural support |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS587916A (en) | 1983-01-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1074930A (en) | Vhf, uhf and superband tuner with automatic switching | |
| US4151557A (en) | Television receiver operating mode selector | |
| LT3635B (en) | Switching scheme for diapasons in tuner | |
| US4167704A (en) | Channel selecting apparatus | |
| KR19990067818A (en) | Synchronous demodulating circuit | |
| JPS6348453B2 (en) | ||
| JPH0138994Y2 (en) | ||
| US4461038A (en) | Television tuner circuit | |
| US4031475A (en) | Electronic channel selecting apparatus | |
| US3965288A (en) | Automatic tuning apparatus | |
| US3996540A (en) | Indicating device for tuning apparatus | |
| US4082964A (en) | Diode switch | |
| KR20000048755A (en) | Multiple preamplifier circuit for a television tuner | |
| US3899760A (en) | Electronic channel address remote control system | |
| KR900005952Y1 (en) | Automatic audio selecting circuit for multi-sound television | |
| KR850001673Y1 (en) | Tv tunner band changing circuit | |
| JPH0666680B2 (en) | TTL circuit | |
| KR900006465B1 (en) | Circuit for signal processing in a picture display device | |
| KR850001125B1 (en) | Tv tunner bend charging circuit | |
| JPS6230344Y2 (en) | ||
| US4081835A (en) | Blanking circuitry for a television receiver video system | |
| KR910001517B1 (en) | Multi-audio signal choosing circuit for television | |
| KR900003703Y1 (en) | Multi tuner appending system for picture in picture function | |
| JPS6237846B2 (en) | ||
| JP3847122B2 (en) | Television tuner band switching circuit |