JPH0342756Y2 - - Google Patents
Info
- Publication number
- JPH0342756Y2 JPH0342756Y2 JP11431784U JP11431784U JPH0342756Y2 JP H0342756 Y2 JPH0342756 Y2 JP H0342756Y2 JP 11431784 U JP11431784 U JP 11431784U JP 11431784 U JP11431784 U JP 11431784U JP H0342756 Y2 JPH0342756 Y2 JP H0342756Y2
- Authority
- JP
- Japan
- Prior art keywords
- switch
- band
- intermediate tap
- receiving
- vhf
- 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
- 230000001360 synchronised effect Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
Landscapes
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Description
【考案の詳細な説明】 〔技術分野〕 本考案はテレビ用選局回路に関する。[Detailed explanation of the idea] 〔Technical field〕 The present invention relates to a television channel selection circuit.
中間タツプ付可変抵抗素子、及びスイツチ素子
からなる、同調電圧供給素子を用いた従来のテレ
ビ用選局回路は、第２図の様なものであつた。
A conventional television channel selection circuit using a tuning voltage supply element consisting of a variable resistance element with an intermediate tap and a switch element is as shown in FIG.
以下にその動作について説明する。 The operation will be explained below.
UHF（以下Ｕと言う）受信時には、バンドスイ
ツチ２をＵに切り換えて、チユーナにＵ駆動電源
UBを供給し、Ｑ１，Ｑ２，Ｑ３，Ｑ４はすべて
オフしているので、同調電圧供給素子１のac間
で、同調電圧が30〜0Vに可変する。VHF高バン
ド（以下VHと言う）受信時には、バンドスイツ
チ２をVHF（以下Ｖと言う）に切り換え、同調電
圧供給素子１のSW１をオン（可変抵抗素子のab
間）する事により、Ｑ１がオン、Ｑ２がオフし、
チユーナにVH駆動電源HBを供給する。 When receiving UHF (hereinafter referred to as U), switch band switch 2 to U, and connect the tuner with U drive power.
Since UB is supplied and Q1, Q2, Q3, and Q4 are all turned off, the tuning voltage varies between 30 and 0 V between AC of the tuning voltage supply element 1. When receiving VHF high band (hereinafter referred to as VH), switch band switch 2 to VHF (hereinafter referred to as V) and turn on SW1 of tuning voltage supply element 1 (variable resistance element ab
), Q1 turns on and Q2 turns off,
Supply VH drive power HB to tuner.
更にHBによりＱ３をオンし、Ｑ４はオフなの
で、ab間で同調電圧が30〜0Vに可変する。VHF
低バンド（以下VLと言う）受信時には、バンド
スイツチ２をＶに切り換え、同調電圧供給素子１
のSW１をオフ（可変抵抗素子のbc間）とする事
により、Ｑ１がオフ、Ｑ２がオンし、チユーナに
VL駆動電源LBを供給する。更にSW２がオンす
る事によりＱ４をオンし、Ｑ３はオフなので、
bc間で同調電圧が30〜0Vに可変する。 Furthermore, since Q3 is turned on by HB and Q4 is turned off, the tuning voltage is varied between 30 and 0V between a and b. VHF
When receiving low band (hereinafter referred to as VL), switch band switch 2 to V and tune voltage supply element 1.
By turning off SW1 (between b and c of the variable resistance element), Q1 turns off and Q2 turns on, and the tuner
Supply VL drive power LB. Furthermore, when SW2 turns on, Q4 turns on, and Q3 turns off, so
Tuning voltage varies from 30 to 0V between b and c.
上述の従来回路は部分点数が多く、かつVL時
には30VラインからＱ４のバイアス抵抗に電流が
消費され、受信バンドによる30Vラインの負荷変
動、及び省電力の点から好ましくない。
The conventional circuit described above has a large number of partial points, and at the time of VL, current is consumed from the 30V line to the bias resistor of Q4, which is undesirable from the viewpoint of load fluctuation of the 30V line depending on the reception band and power saving.
本考案はこの点を改善する目的でなされたもの
である。 The present invention was made with the aim of improving this point.
本考案は同調電圧供給素子の中間タツプ電位
が、ＵとVLで高く、VHで低い事に着目し、こ
れを利用してHB，LBを切り換える事を特徴と
するテレビ用選局回路。
The present invention focuses on the fact that the intermediate tap potential of the tuning voltage supply element is high at U and VL and low at VH, and utilizes this to switch between HB and LB.
本考案のテレビ用選局回路の実施例は第１図で
あり、以下にその動作について説明する。
An embodiment of the television channel selection circuit of the present invention is shown in FIG. 1, and its operation will be described below.
Ｕ受信時には、バンドスイツチ２をＵに切り換
えて、チユーナにUBを供給し、中間タツプｂを
開放する。 When receiving U, band switch 2 is switched to U, UB is supplied to the tuner, and intermediate tap b is opened.
Ｑ１，Ｑ２，Ｄ１はオフ、同調電圧供給素子１
のスイツチ素子の接点も開放となつているので、
ac間で同調電圧が30〜0Vに可変する。 Q1, Q2, D1 are off, tuning voltage supply element 1
Since the contact of the switch element is also open,
Tuning voltage varies from 30 to 0V between AC.
VH受信時には、バンドスイツチ２をＶに切り
換えて、中間タツプｂをスイツチ素子の接点に接
続する。 When receiving VH, the band switch 2 is switched to V and the intermediate tap b is connected to the contact of the switch element.
SW１をオンする事により、中間タツプｂを
OVとし、Ｄ１，Ｑ１がオンし、Ｑ２がオフして
HBを供給し、ab間で同調電圧が30〜0Vに可変
する。 By turning on SW1, middle tap b is turned on.
OV, D1 and Q1 are turned on, and Q2 is turned off.
HB is supplied, and the tuning voltage varies between 30 and 0V between AB.
VL受信時には、バンドスイツチ２をＶに切り
換えて、中間タツプｂをスイツチ素子の接点に接
続する。 When receiving VL, the band switch 2 is switched to V and the intermediate tap b is connected to the contact of the switch element.
SW２をオンする事により、中間タツプｂを
30Vとし、Ｄ１，Ｑ１がオフし、Ｑ２がオンして
LBを供給し、bc間で同調電圧が30〜0Vに可変す
る。 By turning on SW2, middle tap b can be turned on.
Set to 30V, D1 and Q1 are turned off, and Q2 is turned on.
LB is supplied, and the tuning voltage varies from 30 to 0V between b and c.
以上の様に本考案の回路は、従来回路と同等の
機能を有する。 As described above, the circuit of the present invention has the same functions as the conventional circuit.
以上述べた様に本考案によれば、中間タツプ点
の電位が受信バンドにより異なる事を利用して、
バンド駆動電源を切り換える事により、部品点数
の削減（コストダウン）と、消費電力の低減とい
う効果を有する。
As described above, according to the present invention, by taking advantage of the fact that the potential at the intermediate tap point differs depending on the receiving band,
Switching the band drive power supply has the effect of reducing the number of parts (reducing costs) and reducing power consumption.
第１図は本考案の実施例を示す回路図である。
１……同調電圧供給素子、ａ，ｂ，ｃ……中間
タツプ付可変抵抗素子、SW１，SW２……スイ
ツチ素子、２……UHF，VHFバンド切り替えス
イツチ、Ｑ１……HB駆動トランジスタ、Ｑ２…
…LB駆動トランジスタ、Ｄ１……EB，LB切り
換え用ダイオード。
第２図は従来技術による回路図である。
１……同調電圧供給素子、ａ，ｂ，ｃ……中間
タツプ付可変抵抗素子、SW１，SW２……スイ
ツチ素子、２……UHF，VHFバンド切り換えス
イツチ、Ｑ１……HB駆動トランジスタ、Ｑ２…
…LB駆動トランジスタ、Ｑ３……VH可変抵抗
素子切り換えトランジスタ、Ｑ４……VL可変抵
抗素子切り換えトランジスタ。
FIG. 1 is a circuit diagram showing an embodiment of the present invention. 1... Tuning voltage supply element, a, b, c... Variable resistance element with intermediate tap, SW1, SW2... Switch element, 2... UHF, VHF band switching switch, Q1... HB drive transistor, Q2...
...LB drive transistor, D1...EB, LB switching diode. FIG. 2 is a circuit diagram according to the prior art. 1... Tuning voltage supply element, a, b, c... Variable resistance element with intermediate tap, SW1, SW2... Switch element, 2... UHF, VHF band switching switch, Q1... HB drive transistor, Q2...
...LB drive transistor, Q3...VH variable resistance element switching transistor, Q4...VL variable resistance element switching transistor.
Claims (1)
てなる受信バンド切り替えスイツチと、中間タツ
プを有してなる可変抵抗素子および該可変抵抗素
子の摺動子に同期して該中間タツプ付近で切り替
わるスイツチ素子からなる同期電圧供給素子とを
有してなるテレビ用選局回路において、 該バンド切り替えスイツチがVHF受信側に切
り替えられた時に、VHFのハイバンド受信時に
は該中間タツプを接地側に切り替え、VHFのロ
ーバンド受信時には該中間タツプを同調電圧供給
電源に切り替えてなる該スイツチ素子を有してな
ることを特徴とするテレビ用選局回路。[Claims for Utility Model Registration] A receiving band switching switch for switching the band to UHF reception or VHF reception, a variable resistance element having an intermediate tap, and the intermediate tap in synchronization with the slider of the variable resistance element. In a TV channel selection circuit comprising a synchronous voltage supply element consisting of a switch element that switches near the tap, when the band changeover switch is switched to the VHF receiving side, the intermediate tap is grounded when receiving VHF high band. 1. A television channel selection circuit characterized in that the switch element is configured to switch the intermediate tap to the tuning voltage supply power source when receiving VHF low band.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11431784U JPS6133535U (en) | 1984-07-27 | 1984-07-27 | Television tuning circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11431784U JPS6133535U (en) | 1984-07-27 | 1984-07-27 | Television tuning circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6133535U JPS6133535U (en) | 1986-02-28 |
| JPH0342756Y2 true JPH0342756Y2 (en) | 1991-09-06 |
Family
ID=30673339
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11431784U Granted JPS6133535U (en) | 1984-07-27 | 1984-07-27 | Television tuning circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6133535U (en) |
-
1984
- 1984-07-27 JP JP11431784U patent/JPS6133535U/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6133535U (en) | 1986-02-28 |
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