JPS58159031A - Frequency modulation/television receiver - Google Patents
Frequency modulation/television receiverInfo
- Publication number
- JPS58159031A JPS58159031A JP57042030A JP4203082A JPS58159031A JP S58159031 A JPS58159031 A JP S58159031A JP 57042030 A JP57042030 A JP 57042030A JP 4203082 A JP4203082 A JP 4203082A JP S58159031 A JPS58159031 A JP S58159031A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- intermediate frequency
- circuit
- frequency signal
- tuner
- 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
Links
- 238000006243 chemical reaction Methods 0.000 claims description 9
- 239000003990 capacitor Substances 0.000 abstract description 6
- 235000013351 cheese Nutrition 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 230000005236 sound signal Effects 0.000 description 3
- 238000001514 detection method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/3052—Automatic control in amplifiers having semiconductor devices in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver
Landscapes
- Television Receiver Circuits (AREA)
- Circuits Of Receivers In General (AREA)
Abstract
Description
【発明の詳細な説明】
本発明はＦＭ信号とテレビ音声信号の２つを受信し得る
いわゆるＦＭ／ＴＶ受信機に係り、簡単な構成でＡＧＣ
を効果的に作用させることができる優れたＦＭ／ＴＶ受
信機を提供することを目的とするものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a so-called FM/TV receiver capable of receiving two signals, an FM signal and a television audio signal, and which has a simple configuration and is capable of receiving AGC signals.
The object of the present invention is to provide an excellent FM/TV receiver that can operate effectively.
一般にテレビ音声信号に対してＡＧＣ効果を作用させる
場合にはテレビ信号そのものの帯域が６ＭＨｚと非常に
広帯域であるため、ＡＧＣそのものについてもそれが機
能する帯域をできるだけ広帯域にしておく必要がある。Generally, when applying the AGC effect to a television audio signal, the band of the television signal itself is as wide as 6 MHz, so it is necessary to make the band in which the AGC itself functions as wide as possible.
一方、ＦＭ信号はその帯域がテレビ信号に比して著しく
狭く、２００ＫＨｚも離れると隣りのＦＭ信号が存在す
るということがあり得る。On the other hand, the band of an FM signal is significantly narrower than that of a television signal, and it is possible that an adjacent FM signal exists at a distance of 200 KHz.
したがって、テレビ音声信号に対するＡＧＣ回路をその
ままＦＭ信号に対するＡＧＣ回路として用いるとＦＭ受
信時に隣りの不要なＦＭ信号によってＡＧＣ効果が作用
することがあり、本来受信すべきＦＭ信号が、はとんど
受信できないという不都合が生じる。Therefore, if the AGC circuit for TV audio signals is directly used as the AGC circuit for FM signals, the AGC effect may be caused by adjacent unnecessary FM signals during FM reception, and the FM signals that should be received are rarely received. There is an inconvenience that this cannot be done.
本発明はこのような問題に鑑みてなされたものであり、
テレビ音声受信時には広帯域のＡＧＣ回路を動作させＦ
Ｍ受信時には上記広帯域のＡＧＣ回路を不動作にし、強
入方時にのみ上記ＡＧＣ回路に固定の直流電位を供給し
利得を制御するように構成したものである。The present invention was made in view of such problems,
When receiving TV audio, the wideband AGC circuit is activated.
The broadband AGC circuit is made inactive during M reception, and the gain is controlled by supplying a fixed DC potential to the AGC circuit only during strong input.
以下、本発明のＦＭ／ＴＶ受信機について一実施例の図
面とともに説明する。図は本発明のＦＭ／ＴＶ受信機に
おける一実施例の電気的結線図であり、図中、１はＦＭ
／ＴＶアンテナ、２はＦＭ／ＴＶチューナ、３は周波数
変換回路、４は局部発振回路、５は直流増幅回路である
。そして、ｓｌ、ｓ２．ｓ４けＦＭ／ＴＶ切換スイッチ
、ｓ３は手動スイッチ、Ｑｌ、Ｃ２はトランジスタ、Ｒ
１−Ｒ４゜は抵抗、Ｃ１〜Ｃ３はコンデンサ、Ｄ１〜Ｄ
４はダイオード、ＶＲｌは可変抵抗器をそれぞれ示して
いる。Hereinafter, the FM/TV receiver of the present invention will be explained with reference to the drawings of one embodiment. The figure is an electrical connection diagram of an embodiment of the FM/TV receiver of the present invention, and in the figure, 1 indicates the FM/TV receiver.
2 is an FM/TV tuner, 3 is a frequency conversion circuit, 4 is a local oscillation circuit, and 5 is a DC amplifier circuit. And sl, s2. s4 FM/TV selector switch, s3 is manual switch, Ql, C2 is transistor, R
1-R4゜ is a resistor, C1 to C3 are capacitors, D1 to D
4 represents a diode, and VRl represents a variable resistor.
上記実施例において切換スイッチｓ１．ｓ２．ｓ４をテ
レビ 端子に投入したとする。この場合にはア、ンテナ
１でテレビ信号が受信される。アンテナ１で受信された
テレビ信号はチューナ２によって第１中間周波信号ｆＴ
ｖ（５４、２ｅｓＭＨｚ ）に変換され周波数変換回路
３で１ｏ、７ＭＨ２の第２中間周波信号に変換される。In the above embodiment, the changeover switch s1. s2. Suppose you put the s4 into the TV terminal. In this case, the television signal is received by the antenna 1. The television signal received by the antenna 1 is converted into a first intermediate frequency signal fT by the tuner 2.
The signal is converted into a second intermediate frequency signal of 1o, 7 MH2 by the frequency conversion circuit 3.
そして、その出方は次段に伝送されると共に結合コンデ
ンサｃ１ を介してトランジスタＱ、のベースに印加
される。トランジスタＱ１ はバッファーアンプを構成
しており、ベースに印加された信号は抵抗Ｒ２と可変抵
抗器ＶＲ，によって決定される利得でもって増幅される
。The output signal is transmitted to the next stage and applied to the base of the transistor Q via the coupling capacitor c1. Transistor Q1 constitutes a buffer amplifier, and a signal applied to its base is amplified with a gain determined by resistor R2 and variable resistor VR.
そして、その出力は更に結合コンデンサｃ２を介シテヒ
ーク検波器を構成するトランジスタＱ２のベースに印加
される。したがってここで上記出力がピーク検波される
。ピーク検波された出力は脈流であるためコンデンサｃ
３によってこれが平滑される。平滑された信号はオペア
ンプで構成される直流増幅器６に印加されここで直流増
幅される。The output is further applied via a coupling capacitor c2 to the base of a transistor Q2 constituting a shiteheek detector. Therefore, the above output is peak detected here. Since the peak detected output is a pulsating current, the capacitor c
3 smooths this out. The smoothed signal is applied to a DC amplifier 6 composed of an operational amplifier, where it is DC amplified.
そして直流増幅された出力は抵抗Ｒ１ｏを介してＦ Ｍ
／Ｔ Ｖチューナに帰還される。したがってこのループ
によってＡＧＣ効来が作用する。すなわち、テレビ受信
時にはトランジスタＱ４．Ｑ２直流増幅器６が全て動作
状態になシ、広帯域のＡＧＣ効果が作用する。Then, the DC amplified output is passed through resistor R1o to F M
/ Returned to TV tuner. Therefore, the AGC effect acts through this loop. That is, during television reception, transistor Q4. All Q2 DC amplifiers 6 are not in operation, and a wideband AGC effect is exerted.
次に切換スイッチＳ１．Ｓ２．Ｓ４をＦＭ側端子に投入
したとする。この場合にはアンテナ１でＦＭ信号が受信
される。アンテナ１で受信された信号はチー−すによっ
て第１中間周波信号ｆＦＭ （たとえば５７ ＭＨｚ
）に変換され周波数変換回路３によって１０．７ＭＨｚ
の第２中間周波数信号に変換される。第２中間周波信号
は次段に伝送されると共に結合コンデンサＣを介してト
ランジスタＱ１ のベースに印加される。しかしながら
、この場合には切換スイッチＳ４がＦＭ側端子に投入さ
れているためトランジスタＱ１．Ｑ２が共に非動作状態
にある。したがって、トランジスタＱ１のベースに第２
中間周波信号が印加されてもトランジスタＱ２の出力倶
ｊにピーク検波出力が現われない。そして、この場合に
は直流増幅回路６にＶ。。電源が印加されており抵抗Ｒ
７，Ｒ６を介してダイオードＤ２によって決定される電
圧が直流増幅回路６の入力端に印加されている。したが
って、直流増幅回路６の出力端には上記ダイオードＤ２
によって決定さ謁電圧がそのまま現われ、これが抵抗Ｒ
４゜を介してＦＭ／ＴＶチューナ２に帰還される。すな
わち、ＦＭ受信時にはダイオードＤ２によって決定され
る直流電圧がそのままＦＭ／ＴＶチューナ２に帰還され
所望の利得が得られる。Next, selector switch S1. S2. Assume that S4 is connected to the FM side terminal. In this case, the antenna 1 receives the FM signal. The signal received by antenna 1 is converted into a first intermediate frequency signal fFM (e.g. 57 MHz
) and converted to 10.7MHz by the frequency conversion circuit 3.
is converted into a second intermediate frequency signal. The second intermediate frequency signal is transmitted to the next stage and applied to the base of transistor Q1 via coupling capacitor C. However, in this case, since the selector switch S4 is connected to the FM side terminal, the transistor Q1. Q2 are both inactive. Therefore, the second
Even if an intermediate frequency signal is applied, no peak detection output appears at the output j of transistor Q2. In this case, V is applied to the DC amplifier circuit 6. . Power is applied and resistance R
A voltage determined by the diode D2 is applied to the input end of the DC amplifier circuit 6 via 7 and R6. Therefore, the diode D2 is connected to the output terminal of the DC amplifier circuit 6.
The audience voltage determined by appears as it is, and this is the resistance R
It is fed back to the FM/TV tuner 2 via 4°. That is, during FM reception, the DC voltage determined by the diode D2 is directly fed back to the FM/TV tuner 2 to obtain a desired gain.
そして、この状態において手動のスイッチＳ３をオンす
るとＦＭ／ＴＶチー−す２に帰還される直流電位が抵抗
Ｒ−Ｒ、ダイオードＤ３より成る分流回路により、ダイ
オードＤ２によって決定された前記直流電位より低くな
りＦＭ／ＴＶチューナ２の利得がそれだけ低下すること
になる。In this state, when the manual switch S3 is turned on, the DC potential fed back to the FM/TV cheese 2 is lowered by the shunt circuit consisting of the resistor R-R and the diode D3 than the DC potential determined by the diode D2. Therefore, the gain of the FM/TV tuner 2 decreases accordingly.
したがって、ＦＭ受信時においてＦＭ／ＴＶチューナ２
に強入力が印加されたとき上記手動スイッチＳ３をオン
すれば上記Ｆ Ｍ／Ｔ Ｖチー−す２の利得を適当な値
に設定することができる。Therefore, when receiving FM, the FM/TV tuner 2
By turning on the manual switch S3 when a strong input is applied to the FM/TV cheese 2, the gain of the FM/TV cheese 2 can be set to an appropriate value.
尚、テレビ受信時には切換スイッチＳ４がテレビ側端子
に投入されており、ダイオードＤ４を通してスイッチＳ
３に所定の電圧が印加されているため、スイッチＳ３を
オンしてもダイオードＤ３がオフすることになり、スイ
ンｆＳ３のオンオフに関係なくＡＧＣ動作を可能にする
ことができる。In addition, when receiving TV, the selector switch S4 is connected to the TV side terminal, and the switch S4 is connected to the TV side terminal through the diode D4.
Since a predetermined voltage is applied to the switch fS3, the diode D3 is turned off even when the switch S3 is turned on, and the AGC operation can be performed regardless of whether the switch fS3 is turned on or off.
以上実施例より明らかなように本発明のＦＭ／ＴＶ受信
機はアンテナで受信された信号から第１中間周波信号を
得るＦＭ／ＴＶチューナと、ＦＭ／ＴＶチューナによっ
て得られた第１中間周波信号を第２中間周波信号に変換
する周波数変換回路と周波数変換回路によって得られた
第２中間周波信号を増幅し、検波し、直流増幅する回路
と、この回路によって得られた直流信号をＦＭ／ＴＶチ
ューナに帰還し、ＦＭ／ＴＶチューナの利得を制御する
制御ラインと、ＦＭ／ＴＶ切換スイッチとを有し、Ｆ
Ｍ／Ｔ Ｖ切換スイッチをＦＭ側端子に投入したとき上
記第２中間周波信号を増幅し、検波する回路を非動作状
態にし、予め定められた一定直流電圧が上記制御ライン
を介して上記ＦＭ／ＴＶチューナに印加されるように構
成したものであり、テレビ受信時には所 の帯域のＡＧ
Ｃ効果が効果的に作用し、ＦＭ受信時には上記ＡＧＣ作
用が遮断されるため、簡単な構成でテレビ受信時、ＦＭ
受信時 に優れた受信状態を得ることができ、実用上き
わめて有利なものである。As is clear from the above embodiments, the FM/TV receiver of the present invention includes an FM/TV tuner that obtains a first intermediate frequency signal from a signal received by an antenna, and a first intermediate frequency signal obtained by the FM/TV tuner. a frequency conversion circuit that converts the signal into a second intermediate frequency signal; a circuit that amplifies, detects, and amplifies the second intermediate frequency signal obtained by the frequency conversion circuit; and a circuit that amplifies the second intermediate frequency signal obtained by the frequency conversion circuit; It has a control line that returns to the tuner and controls the gain of the FM/TV tuner, and an FM/TV changeover switch.
When the M/TV selector switch is turned on to the FM side terminal, the circuit for amplifying and detecting the second intermediate frequency signal becomes inactive, and a predetermined constant DC voltage is applied to the FM/TV via the control line. It is configured to be applied to the TV tuner, and when receiving TV, the AG of the local band is applied.
C effect works effectively and the above AGC effect is blocked during FM reception, so with a simple configuration, when receiving TV, FM
It is possible to obtain excellent reception conditions during reception, and is extremely advantageous in practice.
図は本発明のＦＭ／ＴＶ受信機における一実施例の電気
的結線図である。
１・・・・・・アンテナ、２・・・・・・チューナ、３
・・・・−・周波数変換回路、４・−・・・・局部発振
回路、６・・・・・・直流増幅回路、Ｑｌ ・・・・・
・バッファーアンプ用トランジスタ、Ｑ２・・・・・・
検波用トランジスタ、Ｓｌ、Ｓ２．Ｓ４・・・・・・Ｆ
Ｍ／ＴＶスイッチ、Ｓ３・・・・・・手動スイッチ。The figure is an electrical connection diagram of an embodiment of the FM/TV receiver of the present invention. 1...Antenna, 2...Tuner, 3
......Frequency conversion circuit, 4...Local oscillation circuit, 6...DC amplifier circuit, Ql...
・Buffer amplifier transistor, Q2...
Detection transistor, Sl, S2. S4...F
M/TV switch, S3...Manual switch.
Claims (1)
Ｆ Ｍ／Ｔ Ｖチー−すと、ＦＭ／ＴＶチ一ナによって
得られた第１中間周波信号を第２中間周波信号に変換す
る周波数変換回路と、周波数変換回路によって得られた
第２中間周波信号を増幅し、検波し、直流増幅する回路
と、この回路によって得られた直流信号をＦＭ／ＴＶチ
ューナに帰還し、Ｆ Ｍ／Ｔ Ｖチューナの利得を制御
する制御ラインと、ＦＭ／ＴＶ切換スイッチとを有し、
ＦＭ／ＴＶ切換スイッチをＦＭ側端子に投入したとき、
上記第２中間周波信号を増幅し、検波する回路を非動作
状態にし、予め定められた一定直流電圧を手配制御ライ
ンを介して上記ＦＭ／ＴＶチューナに印加するように構
成したＦＭ／ＴＶ受信機。The FM/TV team obtains a first intermediate frequency signal from the signal received by the antenna, and the frequency conversion converts the first intermediate frequency signal obtained by the FM/TV channel into a second intermediate frequency signal. A circuit that amplifies the second intermediate frequency signal obtained by the frequency conversion circuit, detects it, and amplifies the DC signal, and returns the DC signal obtained by this circuit to the FM/TV tuner. It has a control line for controlling the gain of the tuner and an FM/TV selector switch,
When the FM/TV selector switch is turned on to the FM side terminal,
An FM/TV receiver configured to amplify and detect the second intermediate frequency signal, put the circuit in a non-operating state, and apply a predetermined constant DC voltage to the FM/TV tuner via the arrangement control line. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57042030A JPS58159031A (en) | 1982-03-16 | 1982-03-16 | Frequency modulation/television receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57042030A JPS58159031A (en) | 1982-03-16 | 1982-03-16 | Frequency modulation/television receiver |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS58159031A true JPS58159031A (en) | 1983-09-21 |
Family
ID=12624766
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57042030A Pending JPS58159031A (en) | 1982-03-16 | 1982-03-16 | Frequency modulation/television receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58159031A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0470502A2 (en) * | 1990-08-06 | 1992-02-12 | Thomson Consumer Electronics, Inc. | First if filter with fixed second half-if trap for use in an FM radio in a television receiver |
| EP0470504A2 (en) * | 1990-08-06 | 1992-02-12 | Thomson Consumer Electronics, Inc. | Fixed RF AGC of a television tuner for FM reception in a television receiver |
| EP0470481A2 (en) * | 1990-08-06 | 1992-02-12 | Thomson Consumer Electronics, Inc. | Stereo FM radio receiver in a television receiver |
| EP0470519A2 (en) * | 1990-08-06 | 1992-02-12 | Thomson Consumer Electronics, Inc. | Mono FM radio in a television receiver |
| EP0472119A2 (en) * | 1990-08-23 | 1992-02-26 | Thomson Consumer Electronics, Inc. | Interrupting the video IF signal path during FM radio mode in a television receiver |
| CN1041784C (en) * | 1991-05-06 | 1999-01-20 | 汤姆森消费电子(法国)有限公司 | Audio level equalization of television sound, broadcast FM and national weather service FM radio signals |
| CN1048374C (en) * | 1990-03-28 | 2000-01-12 | 汤姆森消费电子有限公司 | Amplifier having maximum summed power output from plurality of devices having limited current sinking capability |
| US6633345B2 (en) | 2000-07-26 | 2003-10-14 | Mitsubishi Denki Kabushiki Kaisha | Receiver selectively receiving, demodulating and outputting a tv broadcast signal and an FM radio broadcast signal |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS431808Y1 (en) * | 1964-07-29 | 1968-01-26 | ||
| JPS5739153B2 (en) * | 1976-07-07 | 1982-08-19 |
-
1982
- 1982-03-16 JP JP57042030A patent/JPS58159031A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS431808Y1 (en) * | 1964-07-29 | 1968-01-26 | ||
| JPS5739153B2 (en) * | 1976-07-07 | 1982-08-19 |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1048374C (en) * | 1990-03-28 | 2000-01-12 | 汤姆森消费电子有限公司 | Amplifier having maximum summed power output from plurality of devices having limited current sinking capability |
| EP0470502A2 (en) * | 1990-08-06 | 1992-02-12 | Thomson Consumer Electronics, Inc. | First if filter with fixed second half-if trap for use in an FM radio in a television receiver |
| EP0470504A2 (en) * | 1990-08-06 | 1992-02-12 | Thomson Consumer Electronics, Inc. | Fixed RF AGC of a television tuner for FM reception in a television receiver |
| EP0470481A2 (en) * | 1990-08-06 | 1992-02-12 | Thomson Consumer Electronics, Inc. | Stereo FM radio receiver in a television receiver |
| EP0470519A2 (en) * | 1990-08-06 | 1992-02-12 | Thomson Consumer Electronics, Inc. | Mono FM radio in a television receiver |
| JPH05252467A (en) * | 1990-08-06 | 1993-09-28 | Thomson Consumer Electron Inc | Television receiver |
| CN1046835C (en) * | 1990-08-06 | 1999-11-24 | 汤姆森消费电子有限公司 | Stereo FM radio in television receiver |
| CN1051190C (en) * | 1990-08-06 | 2000-04-05 | 汤姆森消费电子有限公司 | Mono FM radio in television receiver |
| EP0472119A2 (en) * | 1990-08-23 | 1992-02-26 | Thomson Consumer Electronics, Inc. | Interrupting the video IF signal path during FM radio mode in a television receiver |
| CN1041784C (en) * | 1991-05-06 | 1999-01-20 | 汤姆森消费电子(法国)有限公司 | Audio level equalization of television sound, broadcast FM and national weather service FM radio signals |
| US6633345B2 (en) | 2000-07-26 | 2003-10-14 | Mitsubishi Denki Kabushiki Kaisha | Receiver selectively receiving, demodulating and outputting a tv broadcast signal and an FM radio broadcast signal |
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