JPS60121814A - Band switching circuit - Google Patents

Band switching circuit

Info

Publication number
JPS60121814A
JPS60121814A JP23017483A JP23017483A JPS60121814A JP S60121814 A JPS60121814 A JP S60121814A JP 23017483 A JP23017483 A JP 23017483A JP 23017483 A JP23017483 A JP 23017483A JP S60121814 A JPS60121814 A JP S60121814A
Authority
JP
Japan
Prior art keywords
band
diode
parallel
switching circuit
circuit
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.)
Pending
Application number
JP23017483A
Other languages
Japanese (ja)
Inventor
Seiji Takenawa
竹縄 清次
Yoshimasa Seo
瀬尾 宜正
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denso Ten Ltd
Original Assignee
Denso Ten Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Denso Ten Ltd filed Critical Denso Ten Ltd
Priority to JP23017483A priority Critical patent/JPS60121814A/en
Publication of JPS60121814A publication Critical patent/JPS60121814A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03JTUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J5/00Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner
    • H03J5/24Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner with a number of separate pretuned tuning circuits or separate tuning elements selectively brought into circuit, e.g. for waveband selection or for television channel selection
    • H03J5/242Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner with a number of separate pretuned tuning circuits or separate tuning elements selectively brought into circuit, e.g. for waveband selection or for television channel selection used exclusively for band selection
    • H03J5/244Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner with a number of separate pretuned tuning circuits or separate tuning elements selectively brought into circuit, e.g. for waveband selection or for television channel selection used exclusively for band selection using electronic means

Landscapes

  • Channel Selection Circuits, Automatic Tuning Circuits (AREA)

Abstract

PURPOSE:To constitute can electronic tuning radio receiver at low cost by supplying a bias voltage of every band to parallel-connected varactor diodes for the band switching of a radio receiver which is tuned by a series resonance circuit. CONSTITUTION:When a long wave reception band LW and a middle wave reception band MW are switched to select the MW, a transistor (TR)Q1 is turned on to short-circuit a coil L2. Further, when the band MW is selected, a bias voltage is applied to a terminal MW+ and applied to a varactor diode D2 connected in parallel to a varactor diode D1 through a variable resistor RV1, diode D3, and resistance R3. When the LW is selected, the TRQ1 is turned off to connect coils L1 and L2 in series, and a voltage is applied to a terminal LW+ and further applied to the D2 through a variable resistance RV2, diode D4, and resistance R3.

Description

【発明の詳細な説明】 発明の技術分野 本発明は直列共振回路を用いて同調をとる電子同調ラジ
オにおけるハンド切替回路に関するものである。
TECHNICAL FIELD OF THE INVENTION The present invention relates to a hand switching circuit in an electronically tuned radio that uses a series resonant circuit to perform tuning.

従来技術と問題点 電子同調ラジオにおいては、受信周波数に対する同調を
とるために直列共振回路が用いられている。このような
直列共振回路は一般に受信バントを切り替えるために、
コイルと、同調用可変コンデンサの並列コンデンサとを
それぞれ切り替える必要があり、そのためバンド切替回
路と組み合せて用いられる。
Prior Art and Problems In electronically tuned radios, series resonant circuits are used to tune to the received frequency. Such series resonant circuits are generally used to switch receive bands.
It is necessary to switch between the coil and the parallel capacitor of the tuning variable capacitor, so it is used in combination with a band switching circuit.

従来、電子同調ラジオにおいて受信ハンドをロングウェ
ーブ(L W : 150〜300 kllz )とミ
ドルウェーブ(M W : 535−1605 kll
z)とに切り替え゛るためのハンド切替回路としては、
機械的なリレーまたばトランジスタのスイッチを使用し
てコイルおよび並列コンデンサの切り替えを行う方法が
多(用いられていた。
Conventionally, in an electronically tuned radio, the receiving hand is long wave (LW: 150-300 kllz) and middle wave (MW: 535-1605 kllz).
As a hand switching circuit for switching between
Many methods were used to switch the coils and parallel capacitors using mechanical relays or transistor switches.

第1図は、従来の電子同調ラジオにおけるLW−MWハ
ンド切替回路を示している。同図においてLl、L2は
同調用コイルであって、L WハンドではコイルL1.
L2を直列に使用し、MWハンドではコイルL2をスイ
ッチング用トランジスタQ1でショートして、コイルL
lのみを使用する。トランジスタQ、は、MWバンドの
ときハイレベルとなりLWバンドのときローレベルとな
る制御信号MW/LWを、抵抗R2を経て与えられるこ
とによって、このような切替動作を行う。またI)Iは
可変容量ダイオード(ハリキャップ)であって、抵抗R
1を経て同調可変抵抗器’r、Bから可変のチューニン
グバイアスを与えてその容量を変化させることによって
同調をとる。CV、。
FIG. 1 shows an LW-MW hand switching circuit in a conventional electronically tuned radio. In the figure, Ll and L2 are tuning coils, and in the LW hand, coils L1.
L2 is used in series, and in the MW hand, coil L2 is shorted with switching transistor Q1, and coil L2 is used in series.
Use only l. The transistor Q performs such a switching operation by being supplied with a control signal MW/LW, which is at a high level in the MW band and at a low level in the LW band, via the resistor R2. Also, I) I is a variable capacitance diode (Haricap), and the resistor R
Tuning is achieved by applying a variable tuning bias from the tuning variable resistors 'r and B through 1 and changing the capacitance. CV.

cv2は同調周波数範囲を制限するための並列1−リマ
コンデンサであって、MWパン1−ではコンデンサC■
2のみを使用し、LWバンドではこれにリレーからなる
スイッチSWIの接点を介して、コンデンサCvIを並
列に接続して使用する。スイッチSW1は制御信号MW
/LWによって、スイッチング用トランジスクQ1と並
列に動作する。
cv2 is a parallel 1-lima capacitor for limiting the tuning frequency range, and in the MW pan 1-, capacitor C■
In the LW band, a capacitor CvI is connected in parallel to this via the contact of a switch SWI consisting of a relay. Switch SW1 receives control signal MW
/LW operates in parallel with the switching transistor Q1.

なおスイッチSW1としては、トランジスタからなるス
イッチを使用することもできる。
Note that a switch made of a transistor can also be used as the switch SW1.

しかしながらスイッチSW1としてl・ランジスタおよ
びダイオードを使用した場合は、そのオン抵抗によつ−
(同調回路のQが低下するという問題がある。一方スイ
ッチSW1としてリレーを使用すれば、性能的な問題は
生じないが、リレーは一般に高価であって好ましくない
However, when a transistor and a diode are used as the switch SW1, the on-resistance
(There is a problem that the Q of the tuned circuit decreases.On the other hand, if a relay is used as the switch SW1, no performance problem occurs, but relays are generally expensive and undesirable.

発明の目的 本発明はこのような従来技術の問題点を解決しようとす
るものであって、その目的は、直列共振回路を用いて同
調をとる電子同調ラジオにおいて、性能を低下させるこ
となくかつ安fil[iに構成できるハント切替回路を
提供することにある。
OBJECT OF THE INVENTION The present invention attempts to solve the problems of the prior art, and its purpose is to provide an electronically tuned radio that uses a series resonant circuit to perform tuning without degrading performance and safely. The object of the present invention is to provide a hunt switching circuit that can be configured to fil[i.

発明の実施例 第2図は本発明のハンド切替回路の一実施例の構成を示
している。同図において、第1図におけると同じ部分は
同じ番号で示されており、D2は可変容量ダイオ−F(
バリキャップ)、CIはコンデンサ、R3は抵抗、D3
.D4はダイオ−1〜′、RVl、RV2は可変抵抗で
ある。
Embodiment of the Invention FIG. 2 shows the configuration of an embodiment of the hand switching circuit of the invention. In the same figure, the same parts as in FIG. 1 are indicated by the same numbers, and D2 is a variable capacitance diode F (
varicap), CI is a capacitor, R3 is a resistor, D3
.. D4 is a diode 1 to ', and RVl and RV2 are variable resistors.

第2図において1−ランジスクQ、 lによるコイルL
l、L2の切替は、第1図の場合と同様にして行われる
。可変容量ダイオ−FD2は抵抗R3を経て、バンドに
よつ−ζ変化するバイアス電圧を与えられることによっ
て、可変容量ダイオードDIに対する並列容量値を変化
し、これによってバンド切替が行われる。コンデンサC
1はこの際抵抗R1を経て与えられるバイアス電圧と、
抵抗R2を経て与えられるバイアス電圧とを分離する作
用を行う。それぞれのハンドに対応するバイアス電圧は
、MWハンドのとき可変抵抗RV、に電圧MW+が与え
られ、LWバンドのとき可変抵抗RV2に電圧LW+が
与えられることによって、可変抵抗RV、からダイオー
ドD3を経てMWバンドのバイアス電圧が、可変抵抗R
■2がらダイオ−1” l) 4を経てしWハンドのバ
イアス電圧がそれぞれ発生ずる。可変容量ダイオードD
2によって生じる並列容量値は、可変抵抗RvIr R
V2の調整によって、それぞれのバンドに対応して、適
当な値に設定することができる。
In Fig. 2, 1-Landisque Q, coil L by l
Switching between L and L2 is performed in the same manner as in FIG. The variable capacitance diode FD2 is applied with a bias voltage that varies by -ζ depending on the band via the resistor R3, thereby changing the parallel capacitance value with respect to the variable capacitance diode DI, thereby performing band switching. Capacitor C
1 is the bias voltage applied via the resistor R1,
It acts to separate the bias voltage applied via the resistor R2. The bias voltage corresponding to each hand is applied from the variable resistor RV through the diode D3 by applying the voltage MW+ to the variable resistor RV for the MW hand and applying the voltage LW+ to the variable resistor RV2 for the LW band. The bias voltage of the MW band is set by the variable resistor R.
■The bias voltage of the W hand is generated through the 2 and 4 diodes.Variable capacitance diode D
The parallel capacitance value caused by 2 is the variable resistance RvIr R
By adjusting V2, it is possible to set an appropriate value corresponding to each band.

第2図に示されたバンド切替回路では、並列容夕を使用
した場合のスイッチのオン抵抗によって同調回路のQが
低下して性能が低下する想れがなく、またリレーを使用
する場合のようにコストの問題を生じることもない。さ
らに第2図の回路では、MW、LW両バンドの受信周波
数範囲を決定するための可変容量ダイオードD2の容量
値の設定を、個別にかつ連続的に行うことができ、受信
機の調整作業が容易になる。
In the band switching circuit shown in Figure 2, there is no possibility that the on-resistance of the switch will lower the Q of the tuned circuit and degrade the performance when parallel capacitors are used. There is no cost problem. Furthermore, in the circuit shown in Fig. 2, the capacitance value of the variable capacitance diode D2 for determining the reception frequency range of both the MW and LW bands can be set individually and continuously, thereby simplifying the adjustment work of the receiver. becomes easier.

第3図は本発明のバンド切替回路を適用した電子同調ラ
ジオの要部構成例を示している。同図においてアンテナ
から入力した信号は電界効果トランジスタQ2で増幅さ
れ、そのドレインから取り出されてIC,の■のピンか
らトランジスタQ3に加えられる。これによってトラン
ジスタQ4゜Q5を経てピン[相]、Oに接続された、
並列共振回路を構成するトランスT、、 T2に出力を
生じる。
FIG. 3 shows an example of the main part configuration of an electronically tuned radio to which the band switching circuit of the present invention is applied. In the figure, a signal input from an antenna is amplified by a field effect transistor Q2, taken out from its drain, and applied to a transistor Q3 from a pin 2 of the IC. This connects the pin [phase], O through the transistor Q4゜Q5,
An output is generated to transformers T, T2 forming a parallel resonant circuit.

一方ヒン[相]ば電界効果トランジスタQ2のソースに
接続され、トランジスタQ2のソースには第2図に示さ
れたごとき直列共振回路を構成するコイルLI+ L2
が接続されており、これによって入力に応じて電界効果
トランジスタQ2のゲインを変化させる制御が行われて
同調がとられる。トランスT、、T2の2次側の出力は
、ピン◎からトランジスタQ6を経て図示されない次段
のミキサへ加えられる。
On the other hand, the coil LI+L2 is connected to the source of the field effect transistor Q2, and the source of the transistor Q2 is connected to the coil LI+L2 forming a series resonant circuit as shown in FIG.
is connected, and thereby control is performed to change the gain of the field effect transistor Q2 according to the input, thereby achieving tuning. The output of the secondary side of the transformers T, T2 is applied from pin ◎ to the next stage mixer (not shown) via the transistor Q6.

一方、トランジスタQ7.QB、Q9からなる回路は、
直列共振回路に対する切替用の電源供給回路を形成し、
制御信号M W / 1.、 Wのハイレベルとローレ
ベルの変化に応じて、コイル切替え用のスイツヂングト
ランジスタQ、と、可変容量ダイオードI) 2に対す
る制御電圧発生用の可変抵抗RV、、RV2に対して、
それぞれ所要の電源を供給する。
On the other hand, transistor Q7. The circuit consisting of QB and Q9 is
Forms a switching power supply circuit for the series resonant circuit,
Control signal M W /1. , In response to changes in the high and low levels of W, the switching transistor Q for switching the coil and the variable resistor RV for generating a control voltage for the variable capacitance diode I)2, RV2,
Supply the required power to each.

発明の詳細 な説明したように本発明のハント切替回路によ貫ば、直
列共振同調回路の同調用可変コンデンサの並列容量を可
変容量ダイオードによって構成し、この可変容量ダイオ
ードにバンドごとにバイアス電圧を供給して並列容量を
設定するようにしたので、直列共振回路を用いて同調を
とる電子同調ラジオにおいて、性能を低下させることな
くかつ安価に構成できるハント切替回路を実現すること
ができる。
As described in detail, according to the Hunt switching circuit of the present invention, the parallel capacitance of the tuning variable capacitor of the series resonant tuning circuit is constituted by a variable capacitance diode, and a bias voltage is applied to the variable capacitance diode for each band. Since the parallel capacitance is set by supplying the antenna, it is possible to realize a hunt switching circuit that can be constructed at low cost without deteriorating performance in an electronic tuning radio that uses a series resonant circuit to perform tuning.

【図面の簡単な説明】[Brief explanation of drawings]

第1図は従来のハンド切替回路の構成を示す図、第2図
は本発明のハンド切替回路の一実施例の構成を示す図、
第3図は本発明のハント切替回路を適用した電子同調ラ
ジオの要部構成例を示す図である。 L、、L2−一−コイル、I)I、D2−可変容量ダイ
オード、Iマl+ R2+ R3〜抵抗、C3−コンデ
ンサ、RV、、RV2−可変抵抗器
FIG. 1 is a diagram showing the configuration of a conventional hand switching circuit, and FIG. 2 is a diagram showing the configuration of an embodiment of the hand switching circuit of the present invention.
FIG. 3 is a diagram showing an example of the main part configuration of an electronically tuned radio to which the hunt switching circuit of the present invention is applied. L, , L2 - Coil, I) I, D2 - Variable capacitance diode, I + R2 + R3 - Resistor, C3 - Capacitor, RV, , RV2 - Variable resistor

Claims (1)

【特許請求の範囲】[Claims] 直列共振回路における同調用可変コンデンサの並列容量
を切替えるバンド切替回路において、該並列容量を構成
する可変容量クイオートと、該可変容量ダイオ−I゛に
ハンFごとにバイアス電圧を供給する手段とを具えたこ
とを特徴とするハンド切替回路。
A band switching circuit for switching the parallel capacitance of a tuning variable capacitor in a series resonant circuit, comprising: a variable capacitor quart constituting the parallel capacitor; and means for supplying a bias voltage to the variable capacitor diode-I for each arm F. A hand switching circuit characterized by:
JP23017483A 1983-12-05 1983-12-05 Band switching circuit Pending JPS60121814A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP23017483A JPS60121814A (en) 1983-12-05 1983-12-05 Band switching circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP23017483A JPS60121814A (en) 1983-12-05 1983-12-05 Band switching circuit

Publications (1)

Publication Number Publication Date
JPS60121814A true JPS60121814A (en) 1985-06-29

Family

ID=16903764

Family Applications (1)

Application Number Title Priority Date Filing Date
JP23017483A Pending JPS60121814A (en) 1983-12-05 1983-12-05 Band switching circuit

Country Status (1)

Country Link
JP (1) JPS60121814A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1058384A2 (en) * 1999-06-03 2000-12-06 The Whitaker Corporation Circuit for dual band tuning
WO2003012976A1 (en) * 2001-08-02 2003-02-13 C-Mac Quartz Crystals Limited A variable reactance tuning circuit

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1058384A2 (en) * 1999-06-03 2000-12-06 The Whitaker Corporation Circuit for dual band tuning
EP1058384A3 (en) * 1999-06-03 2002-10-30 The Whitaker Corporation Circuit for dual band tuning
WO2003012976A1 (en) * 2001-08-02 2003-02-13 C-Mac Quartz Crystals Limited A variable reactance tuning circuit
GB2378330B (en) * 2001-08-02 2005-08-10 C Mac Quartz Crystals Ltd A variable reactance tuning circuit

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