JPS639149Y2 - - Google Patents
Info
- Publication number
- JPS639149Y2 JPS639149Y2 JP19050382U JP19050382U JPS639149Y2 JP S639149 Y2 JPS639149 Y2 JP S639149Y2 JP 19050382 U JP19050382 U JP 19050382U JP 19050382 U JP19050382 U JP 19050382U JP S639149 Y2 JPS639149 Y2 JP S639149Y2
- Authority
- JP
- Japan
- Prior art keywords
- local
- diode
- supply line
- switch
- fixed terminal
- 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
- 239000003990 capacitor Substances 0.000 claims description 12
- 230000008054 signal transmission Effects 0.000 claims description 7
- 230000035945 sensitivity Effects 0.000 description 7
- 230000002238 attenuated effect Effects 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Landscapes
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Description
【考案の詳細な説明】
イ 考案の分野
本考案はFM・AM受信機のDX（遠距離受信）
−LOCAL（近距離受信）切換回路に関するもの
である。[Detailed explanation of the invention] A. Field of the invention This invention is a DX (long distance reception) for FM/AM receivers.
-This relates to the LOCAL (short distance reception) switching circuit.
ロ 従来技術
従来の回路は、第１図に示す如く、FM／AM2
バンドの場合、２個のスイツチングトランジスタ
を要していた。B. Prior art As shown in Figure 1, the conventional circuit is FM/AM2
In the case of a band, two switching transistors were required.
先づ、FMの場合、スイツチS1をDX状態にす
ると、電源供給線路４より順方向バイアス電圧供
給路１、抵抗R2、ダイオードD1、FM・AM分離
用コイルL1及び第１のスイツチングトランジス
タQ1を介して電流が流れ、ダイオードD1がONす
ることにより、アンテナ入力はFM高周波信号伝
送路５に直列接続されたカツプリングコンデンサ
C1、ダイオードD1及びハイパスフイルタ用コン
デンサC2を介してFMのフロントエンド部２へと
はいつていく。従つて感度は良好となる。スイツ
チS1をLOCAL状態にすると、ダイオードD1は
OFFとなり、アンテナ接続端子６に接続される
アンテナ（図示せず）から入つたアンテナ入力
は、D1の浮遊容量CD及びC2を介してFMフロント
エンド部２へとはいつていく。従つて感度は劣化
する。 First, in the case of FM, when the switch S 1 is set to the DX state, the power supply line 4 connects the forward bias voltage supply line 1, the resistor R 2 , the diode D 1 , the FM/AM separation coil L 1 and the first switch. When current flows through the switching transistor Q1 and the diode D1 turns on, the antenna input is connected to the coupling capacitor connected in series to the FM high frequency signal transmission line 5.
C 1 , diode D 1 and high-pass filter capacitor C 2 to the front end section 2 of the FM. Therefore, the sensitivity is good. When switch S 1 is placed in LOCAL state, diode D 1 becomes
OFF, and the antenna input from the antenna (not shown) connected to the antenna connection terminal 6 goes to the FM front end section 2 via the stray capacitances CD and C2 of D1 . Therefore, sensitivity deteriorates.
次にAMの場合LOCAL切換時はスイツチング
S2によりQ1はOFFとなる為、アンテナ入力は
AM高周波信号伝送路７に直列接続されたC1，L1
及びカツプリングコンデンサC3を介して、AMフ
ロントエンド部３のアンテナ段へとはいる。この
ときDX−LOCAL切換スイツチS1による回路動
作は、LOCAL時に第２のスイツチングトランジ
スタQ2がONして信号はR4にてダンピングされる
形となりアンテナ入力信号は減衰する。一方DX
受信時にはトランジスタQ2がOFFになるので、
アンテナ入力は損失なく、AMフロントエンド部
３に入力され感度は良好となる。 Next, in case of AM, switching when switching to LOCAL
Since Q 1 is OFF due to S 2 , the antenna input is
C 1 and L 1 connected in series to AM high frequency signal transmission line 7
and the coupling capacitor C3 to the antenna stage of the AM front end section 3. At this time, the circuit operation by the DX-LOCAL changeover switch S1 is such that the second switching transistor Q2 is turned on during LOCAL, and the signal is damped by R4 , so that the antenna input signal is attenuated. On the other hand, DX
During reception, transistor Q2 is turned off, so
The antenna input is inputted to the AM front end section 3 without loss and has good sensitivity.
ハ 従来技術の問題点
第１図の場合、２個のスイツチングトランジス
タを用いているためコストアツプになつており、
又、基板パターンもそれだけ複雑になつていた。C. Problems with the conventional technology In the case of Figure 1, the cost is increased because two switching transistors are used.
Moreover, the substrate pattern has also become more complex.
ニ 考案の目的
本考案は斯る点に鑑みFM・AM受信機のDX
−LOCAL切換回路に於いて、従来と同等機能を
維持しながら回路の簡略化を図ることを目的とし
ている。D. Purpose of the invention In view of the above, the present invention is designed to improve the DX of FM/AM receivers.
-The aim is to simplify the LOCAL switching circuit while maintaining the same functionality as the conventional one.
ホ 考案の実施例
第２図は本考案の一実施例を示す回路図であ
る。E. Embodiment of the invention FIG. 2 is a circuit diagram showing an embodiment of the invention.
第２図の回路では、電源供給線路４が通常接続
されているバイパス用コンデンサC0等により高
周波的にはアースと同一視出来る点に着目し、コ
イルL1とAMフロントエンド部３間のAM高周波
信号伝送路７に分割容量C3′，C3″を直列に接続
し、分割容量C3′，C3″の接続点８を抵抗R4を介し
てDX−LOCAL切換スイツチS1のLOCAL側固定
端子LOCALに接続している。そして第２図の回
路で用いていた第２のスイツチングトランジスタ
Q2は用いていない。その他の構成は第１図の回
路と同じである。 In the circuit shown in Fig. 2, we focused on the fact that the power supply line 4 can be regarded as the ground in terms of high frequency due to the bypass capacitor C 0 etc. to which it is normally connected, and the AM Divided capacitances C 3 ′ and C 3 ″ are connected in series to the high-frequency signal transmission line 7, and the connection point 8 of the divided capacitances C 3 ′ and C 3 ″ is connected to the LOCAL of the DX-LOCAL changeover switch S 1 via the resistor R 4 . Connected to the side fixed terminal LOCAL. And the second switching transistor used in the circuit of Figure 2
Q 2 is not used. The other configurations are the same as the circuit shown in FIG.
第２図の回路に於いて、FMバンドのDX受信
時〔スイツチS2がFM側、スイツチS1がDX側〕
のとき。 In the circuit shown in Figure 2, when receiving DX in the FM band [Switch S 2 is on the FM side, switch S 1 is on the DX side]
When.
電源供給線路４より順方向バイアス電圧供給路
１、抵抗R2、ダイオードD1、コイルL1及び第１
スイツチングトランジスタQ1を介して電流が流
れ、ダイオードD1がONすることにより、アンテ
ナ入力はコンデンサC1、ダイオードD1、及びコ
ンデンサC2を介してFMフロントエンド部２に入
る。従つて感度は良好となる。 From the power supply line 4, forward bias voltage supply line 1, resistor R 2 , diode D 1 , coil L 1 and first
Current flows through the switching transistor Q 1 and the diode D 1 is turned on, so that the antenna input enters the FM front end section 2 via the capacitor C 1 , the diode D 1 , and the capacitor C 2 . Therefore, the sensitivity is good.
FMバンドのLOCAL時〔スイツチS2がFM側、
スイツチS1がLOCAL側〕のとき。 When the FM band is LOCAL [Switch S 2 is on the FM side,
When switch S1 is on the LOCAL side].
ダイオードD1はOFFとなり、アンテナ入力は、
ダイオードD1の浮遊容量及びコンデンサC2を介
してFMフロントエンド部２へと入つていく。従
つて感度は劣化する。 Diode D1 is turned OFF, and the antenna input is
It enters the FM front end section 2 via the stray capacitance of the diode D1 and the capacitor C2. Therefore, sensitivity deteriorates.
次にAMバンドのDX受信時〔スイツチS2が
AM側、スイツチS1がDX側〕のとき。 Next, when receiving AM band DX [Switch S 2
AM side, switch S 1 is on DX side].
このときトランジスタQ1はOFFとなるためア
ンテナ入力は損失なくAMフロントエンド部３に
入力され感度は良好となる。 At this time, the transistor Q1 is turned off, so that the antenna input is inputted to the AM front end section 3 without loss, and the sensitivity is good.
AMバンドのLOCAL受信時〔スイツチS2が
AM側、スイツチS1がLOCAL側〕のとき。 When receiving AM band LOCAL [Switch S 2
AM side, switch S 1 is set to LOCAL side].
このときトランジスタQ1はOFFとなるため、
アンテナ入力はコンデンサC1、コイルL1、及び
分割容量C3′，C3″を介してAMフロントエンド部
３へと入るが、アンテナ入力信号の一部は容量
C3′，C3″の接続点８から抵抗R4′及びスイツチS1
を介して電源供給線路４へと流れ、高周波的にア
ースに側路されたのと同等の効果が得られ、アン
テナ入力信号が減衰して感度が劣化する。 At this time, transistor Q 1 is turned off, so
The antenna input enters the AM front end section 3 via the capacitor C 1 , coil L 1 , and split capacitances C 3 ′ and C 3 ″, but a part of the antenna input signal is transmitted through the capacitance.
From connection point 8 of C 3 ′, C 3 ″, resistor R 4 ′ and switch S 1
The antenna flows to the power supply line 4 via the antenna, and an effect equivalent to that of being bypassed to the ground is obtained in terms of high frequency, and the antenna input signal is attenuated and the sensitivity is degraded.
尚、分割容量C3′，C3″は、アンテナ入力信号か
ら見ると直列に接続されているので、分割容量
C3′，C3″の総合容量の値が第１図のコンデンサC3
の容量値と同じになる様に、即ち
１／C3＝１／C3′＋１／C3″ ……(1)
となる様に容量値が選ばれている。 Note that the dividing capacitors C 3 ′ and C 3 ″ are connected in series when viewed from the antenna input signal, so the dividing capacitors C 3 ′ and C 3 ″ are
The total capacitance value of C 3 ′, C 3 ″ is the capacitor C 3 in Figure 1.
The capacitance value is selected so as to be the same as the capacitance value, that is, 1/C 3 =1/C 3 ′+1/C 3 ″ (1).
又電源供給線路４からの直流電流は、分割容量
C3′，C3″にてカツトされるので、分割容量C3′，
C3″の周辺回路に流れる虞れがない。 In addition, the DC current from the power supply line 4 is
Since it is cut at C 3 ′, C 3 ″, the divided capacity C 3 ′,
There is no risk of it flowing into the peripheral circuits of C3 ' '.
ヘ 考案の考果
以上の様に本考案に依れば、従来と同等機能を
維持しながらスイツチングトランジスタを２個か
ら１個に削減したので、コストを下げることが出
来るとともに回路構成が簡略化し、回路の信頼性
の向上及び基板パターンのシンプル化を図ること
が出来、回路の作成も容易となる。F. Results of the invention As described above, according to the invention, the number of switching transistors has been reduced from two to one while maintaining the same function as the conventional one, making it possible to reduce costs and simplify the circuit configuration. , it is possible to improve the reliability of the circuit, simplify the board pattern, and facilitate the creation of the circuit.
第１図は従来のFM・AM受信機のDX−
LOCAL切換回路を示す回路図、第２図は本考案
のFM・AM受信機のDX−LOCAL切換回路を示
す回路図である。
１……順方向バイアス電圧供給路、２……FM
フロントエンド部、３……AMフロントエンド
部、４……電源供給線路、５……FM高周波信号
伝送路、６……アンテナ接続端子、７……AM高
周波信号伝送路、Q1……スイツチングトランジ
スタ、S1……DX−LOCAL切換スイツチ、S2…
…バンド切換スイツチ、C3′，C3″……分割容量。
Figure 1 shows the DX- of a conventional FM/AM receiver.
FIG. 2 is a circuit diagram showing the DX-LOCAL switching circuit of the FM/AM receiver of the present invention. 1...Forward bias voltage supply path, 2...FM
Front end section, 3...AM front end section, 4...Power supply line, 5...FM high frequency signal transmission line, 6...Antenna connection terminal, 7...AM high frequency signal transmission line, Q 1 ...Switching Transistor, S 1 ...DX-LOCAL changeover switch, S 2 ...
…Band selection switch, C 3 ′, C 3 ″…Divided capacity.
Claims (1)
周波信号伝送路に直列接続したダイオードと、コ
レクタ・エミツタ路が前記ダイオードの一端側と
接地間に接続されたスイツチングトランジスタ
と、共通端子が電源供給線路に接続されFM側固
定端子が前記スイツチングトランジスタのベース
に接続されたバンド切換スイツチと、共通端子が
前記電源供給線路に接続されDX側固定端子が前
記ダイオードの順方向バイアス電圧供給路に接続
されLOCAL側固定端子がAM高周波信号伝送路
に直列接続した分割容量の接続点に接続された１
回路のDX−LOCAL切換回路とを備えてなる
FM・AM受信機のDX−LOCAL切換回路。 A diode connected in series to the FM high frequency signal transmission line between the antenna and the FM front end section, a switching transistor whose collector-emitter path is connected between one end of the diode and ground, and a common terminal connected to the power supply line. A band switching switch has a fixed terminal on the FM side connected to the base of the switching transistor, a common terminal is connected to the power supply line, a fixed terminal on the DX side is connected to the forward bias voltage supply line of the diode, and the LOCAL side has a fixed terminal connected to the base of the switching transistor. 1 whose fixed terminal is connected to the connection point of the divided capacitor connected in series to the AM high frequency signal transmission line.
Equipped with a DX-LOCAL switching circuit.
DX-LOCAL switching circuit for FM/AM receiver.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19050382U JPS5994454U (en) | 1982-12-15 | 1982-12-15 | DX-LOCAL switching circuit of FM/AM receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19050382U JPS5994454U (en) | 1982-12-15 | 1982-12-15 | DX-LOCAL switching circuit of FM/AM receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5994454U JPS5994454U (en) | 1984-06-27 |
| JPS639149Y2 true JPS639149Y2 (en) | 1988-03-18 |
Family
ID=30410454
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19050382U Granted JPS5994454U (en) | 1982-12-15 | 1982-12-15 | DX-LOCAL switching circuit of FM/AM receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5994454U (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012164660A1 (en) * | 2011-05-30 | 2012-12-06 | 株式会社メイコー | Screen printing plate and method for using same |
-
1982
- 1982-12-15 JP JP19050382U patent/JPS5994454U/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5994454U (en) | 1984-06-27 |
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