JPS63149630U

JPS63149630U -

Info

Publication number: JPS63149630U
Application number: JP4006387U
Authority: JP
Priority date: 1987-03-20
Filing date: 1987-03-20
Publication date: 1988-10-03

Description

[Brief explanation of the drawing]

第１図は本考案の選局装置の回路図、第２図は
第１図の回路において可変抵抗器Ｒ_１１を変化さ
せたときの同調電圧の変化を示す特性図、第３図
は従来の選局装置の回路図、第４図は本考案およ
び従来において用いられる可変抵抗器Ｒ_１１およ
びバンド切換スイツチＳ_１の構造を説明するため
の構成図、第５図は、第３図の各バンド受信時の
動作を説明するための等価回路図、第６図は第３
図の回路において可変抵抗器Ｒ_１１を変化させた
ときの同調電圧の変化を示す特性図である。１１……チユーナ、Ａ……摺動子、Ｒ_１１……
同調電圧発生用の可変抵抗器、Ｓ_１……ＶＨＦロ
ー、ハイバンド切換用のスイツチ、Ｓ_２，Ｓ_３…
…ＶＨＦ―ＵＨＦ切換用スイツチ、Ｑ_２，Ｑ_４…
…スイツチ素子、Ｑ_１，Ｑ_３……トランジスタ。 Figure 1 is a circuit diagram of the tuning device of the present invention, Figure 2 is a characteristic diagram showing the change in tuning voltage when variable resistor _R11 is changed in the circuit of Figure 1, and Figure 3 is a diagram of the conventional tuning device. FIG. 4 is a circuit diagram of the channel selection device. FIG. 4 is a configuration diagram for explaining the structure of the variable resistor _R11 and band selection switch _S1 used in the present invention and in the conventional method. FIG. An equivalent circuit diagram to explain the operation at the time of reception, Figure 6 is the same as Figure 3.
FIG. 3 is a characteristic diagram showing a change in tuning voltage when variable resistor _R11 is changed in the circuit shown in the figure. 11... Chuyuna, A... Suriko, R ₁₁ ...
Variable resistor for generating tuning voltage, S ₁ ... Switch for switching VHF low and high bands, S ₂ , S ₃ ...
...VHF-UHF switching switch, Q ₂ , Q ₄ ...
...Switch element, Q ₁ , Q ₃ ...transistor.

Claims

[Claims for Utility Model Registration] A first terminal that can be tuned to different channels in at least the first and second bands, to which an operating voltage is supplied, and a second terminal to which a tuning voltage is supplied. a tuner having a terminal and a third terminal to which voltage for band switching is supplied; a resistive element coupled between the fourth and fifth terminals;
It has a tap terminal coupled to the resistive element and a slider capable of sliding on the resistive element, and the fourth terminal and the fifth terminal are connected to a first potential point and a second potential point, respectively. a variable resistor connected to and having a slider connected to a second terminal of the tuner; a first switch element connected between the first potential point and the tap terminal; and the second potential point. and a second switch element connected between the fourth terminal and the tap terminal; when the slider is located between the fourth terminal and the tap terminal, the second switch element is connected to the first switch element; is in a non-conductive state, a first voltage for band switching is supplied to the third terminal of the tuner, and when the slider is located between the fifth terminal and the tap terminal, and the tap terminal a control circuit that makes the first switch element conductive, makes the second switch element non-conductive, and supplies a second voltage for band switching to a third terminal of the tuner when the tuner is in a position corresponding to A channel selection device comprising: and;