JPS5855692B2 - Sweep stop signal generation method - Google Patents
Sweep stop signal generation methodInfo
- Publication number
- JPS5855692B2 JPS5855692B2 JP8743676A JP8743676A JPS5855692B2 JP S5855692 B2 JPS5855692 B2 JP S5855692B2 JP 8743676 A JP8743676 A JP 8743676A JP 8743676 A JP8743676 A JP 8743676A JP S5855692 B2 JPS5855692 B2 JP S5855692B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- signal
- intermediate frequency
- broadcasting
- stop signal
- 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
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
- H03J7/18—Automatic scanning over a band of frequencies
- H03J7/20—Automatic scanning over a band of frequencies where the scanning is accomplished by varying the electrical characteristics of a non-mechanically adjustable element
- H03J7/22—Automatic scanning over a band of frequencies where the scanning is accomplished by varying the electrical characteristics of a non-mechanically adjustable element in which an automatic frequency control circuit is brought into action after the scanning action has been stopped
Landscapes
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
Description
【発明の詳細な説明】
本発明は、自動選局受信機に於ける掃引停止信号発生方
法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for generating a sweep stop signal in an automatic channel selection receiver.
自動選局受信機には、コンデンサーの充放電により掃引
電圧を得てチューニング電圧とする方法、モータにより
機械的に可変コイル若しくはバリアプルコンデンサを駆
動して掃引する方法があり、更に最近に於いては位相同
期ループを利用してディシイタル的に掃引するシンセサ
イザ一方式も提案されている。For automatic tuning receivers, there are two methods: one is to obtain a sweep voltage by charging and discharging a capacitor and use it as a tuning voltage, and the other is to mechanically drive a variable coil or a variable pull capacitor using a motor to sweep. One type of synthesizer that sweeps digitally using a phase-locked loop has also been proposed.
初で、伺れの方式を採るにしても、ある放送を受信した
とき最良の同調点に於いて掃引（方式によって掃引の内
容が異なるが、最も広い意味での掃引）を停止し、その
放送を受信する必要がある。For the first time, even if you adopt the method described above, when a certain broadcast is received, the sweep (sweep in the broadest sense, although the content of the sweep differs depending on the method) is stopped at the best tuning point, and the broadcast is need to receive.
斯かる掃引停止を指示する場合、キャリア（具体的には
中間周波）のレベル検出信号と、周波数偏移を示す８字
特性の零点検出信号との積を掃引停止信号とする方法が
、例えば実公昭４５−６１００号公報にて提案されてい
る。When instructing to stop such a sweep, for example, a method in which the product of the level detection signal of the carrier (specifically, intermediate frequency) and the zero point detection signal of the figure-8 characteristic indicating the frequency shift is used as the sweep stop signal is used. This was proposed in Publication No. 45-6100.
即ち、単に中間周波信号のレベルに基いて掃引を停止さ
せた場合には、同調点からづれた状態にて掃引が停止す
る惧れがあり、同調点からの周波数偏移を示す８字特性
の零点検出信号をも加味して掃引停止信号を発生させる
ことが望しいのである。In other words, if the sweep is stopped simply based on the level of the intermediate frequency signal, there is a risk that the sweep will stop in a state that is shifted from the tuning point. It is desirable to generate the sweep stop signal by also considering the zero point detection signal.
籾で、斯かる掃引停止方法を採った場合、ＡＭ放送の掃
引停止信号を得るに当ってＡＭ放送受信には例等必要の
ないレシオ検波回路等の復調回路を別途設けて、周波数
偏移出力を得る必要がある。When such a sweep stop method is adopted for rice, in order to obtain the sweep stop signal for AM broadcasting, a demodulation circuit such as a ratio detection circuit, which is not necessary for AM broadcast reception, is separately installed, and a frequency shift output is generated. It is necessary to obtain
そこで、不発明に於いては、ＡＭ放送の中間周波信号を
ＦＭ回路側に導き、このＦＭ回路中の復調回路を利用し
てＡＭ放送の零点検出信号を発生させんとするものであ
る。Therefore, in the present invention, the intermediate frequency signal of AM broadcasting is led to the FM circuit side, and the demodulation circuit in this FM circuit is used to generate the zero point detection signal of AM broadcasting.
以下、図面に示す実施例を参照して本発明に就いて詳述
する。The present invention will be described in detail below with reference to embodiments shown in the drawings.
図面はＦＭ放送及びＡＭ放送の両放送が受信可能である
２バンドの自動選局受信機のブロックダイヤグラムを示
すものである。The drawing shows a block diagram of a two-band automatic tuning receiver capable of receiving both FM and AM broadcasts.
図に於いて、１ ａ。１ｂは高周波増幅回路、２ ａ
？ ２ ｂは局部発振回路、３ ａ ＞ ３ ｂはチュ
ーナ部となる混合・周波数変換回路、４ａｙ４ｂは中間
周波増幅回路である。In the figure, 1a. 1b is a high frequency amplification circuit, 2a
? 2b is a local oscillation circuit, 3a>3b is a mixing/frequency conversion circuit serving as a tuner section, and 4ay4b is an intermediate frequency amplification circuit.
尚、添字ａはＡＭ用の回路、添字すはＦＭ用の回路を示
している。Note that the subscript a indicates an AM circuit, and the subscript s indicates an FM circuit.
ＡＭの中間周波増幅回路４ａの出力はダイオード等より
なる検波回路５に印加され、而して、端子６よりＡＭ放
送の音声信号が導出される。The output of the AM intermediate frequency amplification circuit 4a is applied to a detection circuit 5 made of a diode or the like, and an AM broadcast audio signal is derived from a terminal 6.
一方、ＦＭの中間周波増幅回路４ｂの出力は、レシオ検
波回路等の復調回路７及びレベル検出回路８に印加され
る。On the other hand, the output of the FM intermediate frequency amplification circuit 4b is applied to a demodulation circuit 7 such as a ratio detection circuit and a level detection circuit 8.
而して、復調回路７の出力は、周波数偏移を示す８字特
性出力となるから、結局端子９より零点検出信号及びＦ
Ｍ放送の音声信号を得ることができる。Therefore, the output of the demodulation circuit 7 becomes an 8-character characteristic output indicating the frequency deviation, so the zero point detection signal and the F
M broadcast audio signals can be obtained.
また端子１０より、ＦＭ中間周波のレベル検出信号を得
ることができる。Further, from the terminal 10, an FM intermediate frequency level detection signal can be obtained.
そこで、零点検出信号とレベル検出信号とをアンド回路
（図示せず）に導くことにより、ＦＭ放送の掃引停止信
号を得ることができる。Therefore, by guiding the zero point detection signal and the level detection signal to an AND circuit (not shown), a sweep stop signal for FM broadcasting can be obtained.
初で、ＡＭ放送の掃引停止信号を得るには、（ｆ１＋ｆ
２）（但しｆｌはＡＭ放送の中間周波数、ｆ２はＦＭ放
送の中間周波数）にて発振する擬似局部発振回路１１を
設け、この発振出力とＡＭの中間周波信号をＦＭ回路側
の混合・周波数変換回路３ｂに導く。To obtain the AM broadcast sweep stop signal for the first time, (f1+f
2) A pseudo local oscillation circuit 11 is provided that oscillates at the intermediate frequency of AM broadcasting (fl is the intermediate frequency of AM broadcasting, and f2 is the intermediate frequency of FM broadcasting), and this oscillation output and the AM intermediate frequency signal are mixed and frequency converted on the FM circuit side. Leads to circuit 3b.
するとこの回路３ｂより周波数ｆ２の中間周波信号が得
られるから、結局、ＦＭ回路中の復調回路７及びレベル
検出回路８を利用して零点検出信号及びレベル検出信号
を得ることができ、而してこれ等両信号の積の出力とし
てＡＭ放送の掃引停止信号を得られるものである。Then, since an intermediate frequency signal of frequency f2 is obtained from this circuit 3b, it is possible to obtain a zero point detection signal and a level detection signal by using the demodulation circuit 7 and level detection circuit 8 in the FM circuit. A sweep stop signal for AM broadcasting can be obtained as the output of the product of these two signals.
以上述べた本発明に依れば、２バンド以上の自動選局受
信機に於いてＡＭ放送の掃引停止信号を得る場合、ＡＭ
放送の中間周波信号をＦＭ回路側に導き、擬似局部発振
回路の出力と混合することにより、ＦＭの中間周波数を
有する中間周波信号を得、而してＦＭ回路に設けられた
復調回路及びレベル検出回路を利用して零点検出信号及
びレベル検出信号を導出し、而してこれ等の積の出力と
してＡＭ放送の掃引停止信号を得るものであるから、Ａ
Ｍ放送用として別途復調回路及びレベル検出回路を設け
る必要がなく、構成が簡単であり且つ経済的である。According to the present invention described above, when obtaining an AM broadcast sweep stop signal in an automatic tuning receiver for two or more bands, AM
By guiding the broadcasting intermediate frequency signal to the FM circuit side and mixing it with the output of the pseudo local oscillation circuit, an intermediate frequency signal having the FM intermediate frequency is obtained, and the demodulation circuit and level detection provided in the FM circuit are obtained. A circuit is used to derive the zero point detection signal and the level detection signal, and the sweep stop signal for AM broadcasting is obtained as the output of the product of these signals.
There is no need to separately provide a demodulation circuit and a level detection circuit for M broadcasting, and the configuration is simple and economical.
図面は本発明に斯かる掃引停止信号発生方法を達成する
為のブロックダイヤグラムを示す図である。
１ａ、ｌｂは高周波増幅回路、２ ａ 、２ ｂは局部
発振回路、３ ａ 、３ ｂは混合・周波数変換回路、
４ａ、４ｂは中間周波増幅回路、５はＡＭ用の検波回路
、７は復調回路、８はレベル検出回路、１１は擬似局部
発振回路。The drawing shows a block diagram for implementing the method of generating a sweep stop signal according to the present invention. 1a and lb are high frequency amplifier circuits, 2a and 2b are local oscillation circuits, 3a and 3b are mixing/frequency conversion circuits,
4a and 4b are intermediate frequency amplification circuits, 5 is an AM detection circuit, 7 is a demodulation circuit, 8 is a level detection circuit, and 11 is a pseudo local oscillation circuit.
Claims (1)
両方が受信可能である２バンド以上の自動選局受信機（
ＡＭの中間周波数をｆｌ、ＦＭの中間周波数をｆ２とす
る）に於ける掃引停止信号発生方法であって、キャリア
のレベル検出信号と周波数偏移を示す８字特性の零点検
出信号の積により掃引停止信号を発生させる際して、 ＦＭ放送の零点検出信号を得る場合にはＦＭ回路中に設
けられた復調回路を利用し、 ＡＭ放送の零点検出信号を得る場合には、ＡＭ放送の中
間周波信号をＦＭ回路に導き、この周波数ｆ１の中間周
波信号と擬似局部発振回路の発振出力とをＦＭ回路の混
合・周波数変換回路に印加して周波数ｆ２の中間周波信
号を得、この中間周波信号を前記ＦＭ回路中の復調回路
に印加し、而してＡＭ放送の零点検出信号を得ることを
特徴とする掃引停止信号発生方法。[Claims] An automatic tuning receiver with two or more bands that can receive both IFM (frequency modulation) and AM (amplitude modulation) broadcasts (
This is a sweep stop signal generation method in which the intermediate frequency of AM is fl and the intermediate frequency of FM is f2. When generating a stop signal, use the demodulation circuit installed in the FM circuit to obtain the zero point detection signal for FM broadcasting, and use the intermediate frequency of AM broadcasting to obtain the zero point detection signal for AM broadcasting. The signal is guided to the FM circuit, and this intermediate frequency signal of frequency f1 and the oscillation output of the pseudo local oscillation circuit are applied to the mixing/frequency conversion circuit of the FM circuit to obtain an intermediate frequency signal of frequency f2. A method for generating a sweep stop signal, characterized in that the sweep stop signal is applied to a demodulation circuit in the FM circuit, thereby obtaining a zero point detection signal for AM broadcasting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8743676A JPS5855692B2 (en) | 1976-07-19 | 1976-07-19 | Sweep stop signal generation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8743676A JPS5855692B2 (en) | 1976-07-19 | 1976-07-19 | Sweep stop signal generation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5311509A JPS5311509A (en) | 1978-02-02 |
| JPS5855692B2 true JPS5855692B2 (en) | 1983-12-10 |
Family
ID=13914806
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8743676A Expired JPS5855692B2 (en) | 1976-07-19 | 1976-07-19 | Sweep stop signal generation method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5855692B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55114041A (en) * | 1979-02-26 | 1980-09-03 | Hitachi Ltd | Fm/am radio system |
| US4580286A (en) * | 1984-03-26 | 1986-04-01 | Sprague Electric Company | Noise activated mute for FM reception in an AM/FM radio receiver |
-
1976
- 1976-07-19 JP JP8743676A patent/JPS5855692B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5311509A (en) | 1978-02-02 |
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