JPH0528819Y2 - - Google Patents
Info
- Publication number
- JPH0528819Y2 JPH0528819Y2 JP1986109829U JP10982986U JPH0528819Y2 JP H0528819 Y2 JPH0528819 Y2 JP H0528819Y2 JP 1986109829 U JP1986109829 U JP 1986109829U JP 10982986 U JP10982986 U JP 10982986U JP H0528819 Y2 JPH0528819 Y2 JP H0528819Y2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- circuit
- frequency
- stop
- counter
- 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 - Lifetime
Links
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 claims description 11
- 230000010355 oscillation Effects 0.000 description 8
- 230000003321 amplification Effects 0.000 description 6
- 238000003199 nucleic acid amplification method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 239000000919 ceramic Substances 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Landscapes
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
Description
【考案の詳細な説明】
(イ) 産業上の利用分野
本考案は、オートサーチ機能を有するシンセサ
イザ受信機に用いられる停止信号発生回路に関す
るもので、特にIF（中間周波）信号の周波数を計
数して停止信号を発生する停止信号発生回路の改
良に関する。[Detailed description of the invention] (a) Industrial application field The present invention relates to a stop signal generation circuit used in a synthesizer receiver having an auto-search function, and in particular, the invention relates to a stop signal generation circuit used in a synthesizer receiver having an auto-search function. The present invention relates to an improvement in a stop signal generation circuit that generates a stop signal.
(ロ) 従来の技術
オートサーチ機能を有するシンセサイザ受信機
においては、オートサーチ動作により局の存在す
る周波数が選択されたとき、前記オートサーチを
停止させる為の停止信号を発生させなければなら
ない。しかして、従来一般には、中間周波段から
得られる電界強度を表わす信号（例えばシグナル
メータ信号）や検波段から得られるＳカーブ信号
に基づき、前記停止信号を作成していた。しかし
ながら、前記シグナルメータ信号や前記Ｓカーブ
信号は、その検出帯域幅をあまり狭く出来ないの
で、1KHzステツプでサーチを行なうAM受信機
や、25KHzステツプでサーチを行なうFM受信機
に対して前記停止信号を使用すると、完全同調点
近傍の周波数でオートサーチが停止し、完全同調
点での受信が達成出来なくなるという問題があつ
た。その為、特開昭60−69909号公報に示される
如く、前記シグナルメータ信号やＳカーブ信号を
局近傍検出に用い、中間周波信号を計数するカウ
ンタの出力信号を用いて完全同調点でのオートサ
ーチ停止を行なう方法が提案され、実用に供され
ている。(b) Prior Art In a synthesizer receiver having an auto-search function, when a frequency where a station exists is selected by the auto-search operation, a stop signal must be generated to stop the auto-search. Conventionally, the stop signal has generally been created based on a signal representing the electric field strength obtained from the intermediate frequency stage (for example, a signal meter signal) or an S-curve signal obtained from the detection stage. However, since the detection bandwidth of the signal meter signal and the S-curve signal cannot be narrowed very much, the stop signal is not suitable for AM receivers that search in 1KHz steps or FM receivers that search in 25KHz steps. When using this, there was a problem that the auto search stopped at a frequency near the perfect tuning point, making it impossible to achieve reception at the perfect tuning point. Therefore, as shown in Japanese Unexamined Patent Publication No. 60-69909, the signal meter signal and S curve signal are used for detecting the vicinity of the station, and the output signal of a counter that counts intermediate frequency signals is used to perform automatic operation at the complete tuning point. A method of stopping the search has been proposed and put into practical use.
第２図は、前記公報に記載されたいわゆるIF
カウント方式の停止信号発生回路を示すもので、
アンテナ１に受信されたAM放送信号は、RF（ラ
ジオ周波）増幅回路２で増幅され、混合回路３で
局部発振回路４の出力信号と混合されてIF信号
に変換される。前記IF信号は、入力トランス５、
セラミツクフイルタ６、IF増幅回路７及び出力
トランス８から成るIF増幅段９で増幅された後、
検波回路１０で検波され後段に伝送される。オー
トサーチを行なう場合は、PLL回路１１から発
生するオートサーチ信号により局部発振回路４の
出力信号周波数、及びRF増幅回路２の同調周波
数を可変する。オートサーチの１ステツプを1K
Hzとすれば、PLL回路１１の出力信号の変化に
応じて、局部発振回路４の出力信号周波数が1K
Hzずつ変化し、順次放送局のサーチを行なうこと
が出来る。 Figure 2 shows the so-called IF described in the above publication.
This shows a count-type stop signal generation circuit.
An AM broadcast signal received by an antenna 1 is amplified by an RF (radio frequency) amplification circuit 2, mixed with an output signal of a local oscillation circuit 4 by a mixing circuit 3, and converted into an IF signal. The IF signal is input to an input transformer 5,
After being amplified by an IF amplification stage 9 consisting of a ceramic filter 6, an IF amplification circuit 7, and an output transformer 8 ,
The signal is detected by the detection circuit 10 and transmitted to the subsequent stage. When performing an auto search, the output signal frequency of the local oscillation circuit 4 and the tuning frequency of the RF amplifier circuit 2 are varied by the auto search signal generated from the PLL circuit 11. 1K for 1 step of auto search
Hz, the output signal frequency of the local oscillator circuit 4 changes to 1K in response to changes in the output signal of the PLL circuit 11.
The frequency changes in Hz increments, allowing you to search for broadcast stations in sequence.
オートサーチが進み、ある周波数1のAM放送
信号が受信され、その時の局部発振回路４の出力
信号周波数が2であるとすれば、IF信号の周波数
は2−1になる。例えば、f1＝810KHz，f2＝
1260KHzとすれば、IF信号の周波数は450KHzと
なる。また、前記AM放送信号が8KHzで変調さ
れているとすれば、450KHz±8KHzのサイドピー
クが発生する。この状態を第３図イに示す。その
際、セラミツクフイルタ６の帯域を第３図イの一
点鎖線の如く設定すれば、前記IF信号がセラミ
ツクフイルタ６を通過し、IF増幅回路７で増幅
されて検波回路１０に印加される。その時、前記
検波回路１０の入力端に得られるIF信号は、増
幅回路１２に印加され、該増幅回路１２で増幅さ
れた後カウンタ１３で計数される。そして、計数
結果が450KHzとなるので、判別回路１４の出力
端に正しいIF信号であることを示す出力信号が
発生し、停止信号発生部１５から停止信号が発生
するので、PLL回路１１によるオートサーチが
停止し、前記周波数1のAM放送信号の継続受信
が達成される。 Assuming that the auto search progresses and an AM broadcast signal of a certain frequency 1 is received, and the output signal frequency of the local oscillation circuit 4 at that time is 2 , the frequency of the IF signal becomes 2 - 1 . For example, f 1 = 810KHz, f 2 =
If it is 1260KHz, the frequency of the IF signal will be 450KHz. Furthermore, if the AM broadcast signal is modulated at 8KHz, side peaks of 450KHz±8KHz occur. This state is shown in Figure 3A. At this time, if the band of the ceramic filter 6 is set as shown by the dashed line in FIG. At this time, the IF signal obtained at the input terminal of the detection circuit 10 is applied to the amplifier circuit 12, amplified by the amplifier circuit 12, and then counted by the counter 13. Then, since the counting result is 450KHz, an output signal indicating that it is a correct IF signal is generated at the output end of the discrimination circuit 14, and a stop signal is generated from the stop signal generator 15, so the auto search by the PLL circuit 11 is performed. is stopped, and continuous reception of the AM broadcast signal of frequency 1 is achieved.
従つて、第２図の如き停止信号発生回路を用い
れば、放送信号を受信し、IF信号の周波数が正
しい値になつたときオートサーチを停止させるこ
とが出来るので、完全同調点での受信を達成出来
る。 Therefore, by using a stop signal generation circuit like the one shown in Figure 2, it is possible to receive the broadcast signal and stop the auto search when the frequency of the IF signal reaches the correct value, so reception at the perfect tuning point is possible. It can be achieved.
(ハ) 考案が解決しようとする問題点
しかしながら、第２図の如き停止信号発生回路
を用いた場合、IF信号のサイドピークに起因し
てオートサーチが誤停止し、完全同調点における
受信が達成出来ないという問題があつた。例え
ば、810KHzのAM放送信号を受信したとき、局
部発振回路４の出力信号周波数を1270KHzとすれ
ば、IF信号の周波数は460KHzになる。そして、
変調周波数を8KHzとすれば、第３図ロに示す如
く、下側サイドピーク（460KHz−8KHz）がセラ
ミツクフイルタ６の帯域内を通過し、増幅回路１
２で増幅され、カウンタ１３で計数されるので、
前記下側サイドピークの計数結果（450KHz＋2K
Hz）が判別回路１４の許容範囲内に入ると、オー
トサーチが停止してしまう。その場合、前記判別
回路１４の許容範囲を狭くすればよいが、前記許
容範囲を狭くしすぎると、正しいIF信号の周波
数がわずかに変動しても停止信号が発生しなくな
るので、根本的な解決にならない。この現象は、
変調周波数が高いAMステレオ放送の受信時に特
に顕著となる。(c) Problems to be solved by the invention However, when using a stop signal generation circuit as shown in Figure 2, auto search stops erroneously due to side peaks of the IF signal, and reception at a perfect tuning point is achieved. There was a problem that I couldn't do it. For example, when an 810KHz AM broadcast signal is received, if the output signal frequency of the local oscillation circuit 4 is 1270KHz, the frequency of the IF signal will be 460KHz. and,
If the modulation frequency is 8KHz, the lower side peak (460KHz-8KHz) passes within the band of the ceramic filter 6, as shown in Figure 3B, and the amplifier circuit 1
Since it is amplified by 2 and counted by counter 13,
Counting results of the lower side peak (450KHz + 2K
Hz) falls within the allowable range of the discrimination circuit 14, the auto search will stop. In that case, the tolerance range of the discrimination circuit 14 can be narrowed, but if the tolerance range is too narrow, the stop signal will not be generated even if the frequency of the correct IF signal changes slightly, so there is no fundamental solution. do not become. This phenomenon is
This is especially noticeable when receiving AM stereo broadcasts with high modulation frequencies.
(ニ) 問題点を解決するための手段
本考案は、上述の点に鑑み成されたもので、カ
ウンタで計数されるIF信号を、中間周波段に配
置されるフイルタよりも前段の伝送路から取り出
す手段を設けた点を特徴とする。(d) Means for solving the problem The present invention was developed in view of the above-mentioned points. It is characterized by having a means for taking it out.
(ホ) 作用
本考案に依れば、放送局の配置間隔よりも広い
帯域内のIF信号を計数の為に使用出来るので、
正しいIF信号の周波数の近傍でオートサーチが
停止するのを防止出来る。(E) Effect According to the present invention, IF signals within a band wider than the broadcasting station arrangement interval can be used for counting.
This can prevent auto search from stopping near the correct IF signal frequency.
(ヘ) 実施例
第１図は、本考案の一実施例を示す回路図で、
１６は入力端が混合回路３の出力端に接続され、
セラミツクフイルタ６よりも広い帯域を有するバ
ンドパスフイルタである。尚、第１図におけるそ
の他の回路素子は、第２図のそれと同一に付、同
一の符号を付し、説明を省略する。(F) Embodiment Figure 1 is a circuit diagram showing an embodiment of the present invention.
16 has an input end connected to the output end of the mixing circuit 3,
This is a bandpass filter having a wider band than the ceramic filter 6. Note that other circuit elements in FIG. 1 are designated the same as those in FIG. 2, are given the same reference numerals, and will not be described further.
しかして、前記バンドパスフイルタ１６は、
450KHzの中心周波数を有し、±12KHz程度の広い
帯域を有するものである。いま、受信されたAM
放送信号の周波数を810KHz、局部発振回路４の
出力信号周波数を1270KHzとすれば、IF信号の周
波数は460KHzとなり、その時の変調周波数が8K
Hzであれば、第４図に示す如く、460KHzのIF信
号と460KHz−8KHzの下側サイドピークとがバン
ドパスフイルタ１６の帯域（一点鎖線）を通過す
る。そして、前記IF信号及び下側サイドピーク
は、増幅回路１２で増幅された後カウンタ１３で
計数されるが、レベルの大なるIF信号が主に計
数される為、計数結果は460KHzとなる。前記計
数結果は、判別回路１４において判別されるが、
前記判別回路１４の許容範囲を数ＫHz（例えば±
2KHz）に設定すれば、前記計数結果が正しくな
いと判別され、停止信号が発生せず、オートサー
チが継続する。そして、局部発振回路４の発振周
波数が変化し、IF信号の周波数が450KHzになる
と、判別回路１４が正しいIF信号であるとの判
別を行ない、停止信号が発生してオートサーチが
停止する。 Therefore, the bandpass filter 16 is
It has a center frequency of 450KHz and a wide band of approximately ±12KHz. AM currently received
If the frequency of the broadcast signal is 810KHz and the output signal frequency of local oscillation circuit 4 is 1270KHz, the frequency of the IF signal is 460KHz, and the modulation frequency at that time is 8K.
Hz, the IF signal of 460 KHz and the lower side peak of 460 KHz-8 KHz pass through the band of the bandpass filter 16 (dotted chain line), as shown in FIG. The IF signal and the lower side peak are amplified by the amplifier circuit 12 and then counted by the counter 13. Since the IF signal with a high level is mainly counted, the counting result is 460 KHz. The counting result is discriminated by the discriminating circuit 14,
The permissible range of the discrimination circuit 14 is set to several KHz (for example, ±
2KHz), the counting result is determined to be incorrect, a stop signal is not generated, and the auto search continues. Then, when the oscillation frequency of the local oscillation circuit 4 changes and the frequency of the IF signal becomes 450 KHz, the discrimination circuit 14 discriminates that it is a correct IF signal, generates a stop signal, and stops the auto search.
バンドパスフイルタ１６の通過帯域は、放送局
の配置間隔（日本のAM放送の場合9KHz）より
も大に設定される。望ましくは、更に前記通過帯
域は前記配置間隔の２倍よりも小に設定される。
そうすることにより、サイドピークに起因する誤
停止を防止出来るとともに、隣接チヤンネル妨害
に起因する誤停止も防止出来る。 The passband of the bandpass filter 16 is set to be larger than the arrangement interval of broadcasting stations (9 KHz in the case of Japanese AM broadcasting). Preferably, the passband is set to be smaller than twice the arrangement interval.
By doing so, it is possible to prevent erroneous stopping due to side peaks, and also prevent erroneous stopping due to adjacent channel interference.
尚、第１図の実施例の場合は、局部発振回路３
の出力端に得られるIF信号を、バンドパスフイ
ルタ１６を介して増幅回路１２に設定されてお
り、混合回路３から極度に異常な周波数のIF信
号が発生しない場合は、前記バンドパスフイルタ
１６の機能をRF増幅回路２で代用し、前記バン
ドパスフイルタ１６を除去することが出来る。そ
の場合、混合回路３の出力信号は、直接増幅回路
１２に印加され、該増幅回路で増幅された後カウ
ンタ１３で計数されることになる。また、第１図
の実施例においては、混合回路３の出力端から計
数されるIF信号を取り出しているが、前記IF信
号の取り出しは、IF増幅段９で帯域制限を受け
る前の伝送路の任意の位置から行なうことが出来
る。 In the case of the embodiment shown in FIG. 1, the local oscillation circuit 3
The IF signal obtained at the output end of the bandpass filter 16 is set to the amplifier circuit 12 through the bandpass filter 16. If the mixing circuit 3 does not generate an IF signal with an extremely abnormal frequency, the bandpass filter 16 The function can be replaced by the RF amplifier circuit 2 and the bandpass filter 16 can be removed. In that case, the output signal of the mixing circuit 3 is directly applied to the amplifier circuit 12, amplified by the amplifier circuit, and then counted by the counter 13. In addition, in the embodiment shown in FIG. 1, the IF signal counted from the output end of the mixing circuit 3 is taken out, but the IF signal is taken out from the transmission line before being band limited by the IF amplification stage 9 . It can be done from any position.
(ト) 考案の効果
以上述べた如く、本考案に依れば、IF増幅段
のフイルタにより帯域制限を受ける前のIF信号
を計数することにより停止信号を発生する様にし
ているので、IF信号のサイドピークに起因する
オートサーチの誤停止を確実に防止出来る。(G) Effect of the invention As described above, according to the invention, the stop signal is generated by counting the IF signal before it is band limited by the filter in the IF amplification stage, so the IF signal It is possible to reliably prevent the automatic search from stopping erroneously due to side peaks.
第１図は、本考案の一実施例を示す回路図、第
２図は従来の停止信号発生回路を示す回路図、第
３図イ及びロは第２図の説明に供する為の特性
図、第４図は本考案の説明に供する為の特性図で
ある。
３……混合回路、９……IF増幅段、１３……
カウンタ、１４……判別回路、１５……停止信号
発生部、１６……バンドパスフイルタ。
FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing a conventional stop signal generation circuit, and FIG. 3 A and B are characteristic diagrams for explaining FIG. FIG. 4 is a characteristic diagram for explaining the present invention. 3...Mixing circuit, 9 ...IF amplification stage, 13...
Counter, 14...Discrimination circuit, 15...Stop signal generation section, 16...Band pass filter.
Claims (1)
該カウンタの計数結果が所定値か否か判別する判
別回路と、該判別回路の出力信号に応じてオート
サーチを停止させる信号を発生する停止信号発生
部とを備える停止信号発生回路において、中間周
波段に配置されるフイルタによつて帯域制限を受
ける前の中間周波信号を、前記カウンタの入力信
号として供給する手段を設け、中間周波信号のサ
イドピークにおけるオートサーチの誤停止を防止
したことを特徴とする停止信号発生回路。 a counter that counts the frequency of the intermediate frequency signal;
A stop signal generation circuit includes a determination circuit that determines whether the count result of the counter is a predetermined value or not, and a stop signal generation section that generates a signal to stop auto search according to an output signal of the determination circuit. A means is provided for supplying an intermediate frequency signal before being band limited by a filter disposed in the wave stage as an input signal to the counter, thereby preventing erroneous stopping of auto search at a side peak of the intermediate frequency signal. Stop signal generation circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1986109829U JPH0528819Y2 (en) | 1986-07-17 | 1986-07-17 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1986109829U JPH0528819Y2 (en) | 1986-07-17 | 1986-07-17 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6316718U JPS6316718U (en) | 1988-02-03 |
| JPH0528819Y2 true JPH0528819Y2 (en) | 1993-07-23 |
Family
ID=30988288
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1986109829U Expired - Lifetime JPH0528819Y2 (en) | 1986-07-17 | 1986-07-17 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0528819Y2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2563613Y2 (en) * | 1991-01-14 | 1998-02-25 | 株式会社ケンウッド | Tuning equipment |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6069909A (en) * | 1983-09-26 | 1985-04-20 | Sanyo Electric Co Ltd | Automatic channel selecting device |
| JPS6032832B2 (en) * | 1978-07-26 | 1985-07-30 | シチズン時計株式会社 | electronic clock |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6032832U (en) * | 1983-08-09 | 1985-03-06 | パイオニア株式会社 | Receiver automatic channel selection device |
-
1986
- 1986-07-17 JP JP1986109829U patent/JPH0528819Y2/ja not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6032832B2 (en) * | 1978-07-26 | 1985-07-30 | シチズン時計株式会社 | electronic clock |
| JPS6069909A (en) * | 1983-09-26 | 1985-04-20 | Sanyo Electric Co Ltd | Automatic channel selecting device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6316718U (en) | 1988-02-03 |
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