JPH01113472U - - Google Patents
Info
- Publication number
- JPH01113472U JPH01113472U JP698588U JP698588U JPH01113472U JP H01113472 U JPH01113472 U JP H01113472U JP 698588 U JP698588 U JP 698588U JP 698588 U JP698588 U JP 698588U JP H01113472 U JPH01113472 U JP H01113472U
- Authority
- JP
- Japan
- Prior art keywords
- gain control
- frequency signal
- video
- control means
- output
- 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
- 238000001514 detection method Methods 0.000 claims description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000003321 amplification Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
Landscapes
- Television Receiver Circuits (AREA)
Description
第１図はこの考案の一実施例の構成を示す回路
図、第２図は第１図の動作を説明するための特性
図、第３図は第１図の具体的構成の一例を示す回
路図、第４図はこの考案の第２の実施例の構成を
示す回路図、第５図は従来のＡＧＣ装置に一例の
動作を示す特性図、第６図は従来のＡＧＣ装置の
他の例の構成を示す回路図である。
１１……アンテナ、１４……チユーナ、１５…
…映像中間周波増幅回路、１６……映像検波回路
、２１……第１のＡＧＣ回路、２２……第２のＡ
ＧＣ回路、２３……減衰回路、２４……第３のＡ
ＧＣ回路、１５１，１５２……増幅回路、Ｑ１〜
Ｑ６……トランジスタ、Ｒ１〜Ｒ９……抵抗、Ｖ
Ｒ……可変抵抗、Ｉ……低電流源、Ｄ……ツエナ
ーダイオード。
Fig. 1 is a circuit diagram showing the configuration of an embodiment of this invention, Fig. 2 is a characteristic diagram for explaining the operation of Fig. 1, and Fig. 3 is a circuit showing an example of the specific configuration of Fig. 1. 4 is a circuit diagram showing the configuration of a second embodiment of this invention, FIG. 5 is a characteristic diagram showing the operation of an example of a conventional AGC device, and FIG. 6 is another example of a conventional AGC device. FIG. 11...Antenna, 14...Chyuna, 15...
...Video intermediate frequency amplification circuit, 16...Video detection circuit, 21...First AGC circuit, 22...Second A
GC circuit, 23...attenuation circuit, 24...third A
GC circuit, 151, 152...Amplification circuit, Q1~
Q6...transistor, R1-R9...resistance, V
R...Variable resistor, I...Low current source, D...Zener diode.
Claims (1)
周波信号を選択し、これを映像中間周波信号に変
換する選択手段と、 この選局手段から出力される上記映像と中間周
波信号を映像検波する映像検波手段と、 この映像検波手段の検波出力が一定レベルとな
るように、上記映像中間周波信号の利得を制御す
る第１の利得制御手段と、 この第１の利得制御手段の制御出力に従つて、
この第１の利得制御手段が利得制御動作を開始す
る電界強度点よりは高い点で、上記映像検波出力
が一定となるように、上記選択手段に対する上記
アンテナで受信された上記高周波信号の入力レベ
ルを制御る第２の利得制御手段と、 この第２の利得制御手段の制御出力に従つて、
この第２の利得制御手段が利得制御動作を開始す
る電界強度点よりは高い点で、上記映像検波出力
が一定となるように、上記選択手段で選択された
上記高周波使信号の利得を制御る第３の利得制御
手段とを具備した自動利得制御装置。[Claims for Utility Model Registration] Selection means for selecting a high frequency signal of a desired channel from the reception input of an antenna and converting it into a video intermediate frequency signal; and the video and intermediate frequency signal output from the channel selection means. a first gain control means for controlling the gain of the video intermediate frequency signal so that the detection output of the video detection means is at a constant level; According to the control output,
The input level of the high frequency signal received by the antenna to the selection means is set such that the video detection output is constant at a point higher than the field intensity point at which the first gain control means starts the gain control operation. a second gain control means for controlling; and according to the control output of the second gain control means,
The second gain control means controls the gain of the high frequency signal selected by the selection means so that the video detection output becomes constant at a point higher than the field strength point at which the gain control operation is started. an automatic gain control device comprising: third gain control means;
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP698588U JPH01113472U (en) | 1988-01-22 | 1988-01-22 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP698588U JPH01113472U (en) | 1988-01-22 | 1988-01-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01113472U true JPH01113472U (en) | 1989-07-31 |
Family
ID=31211614
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP698588U Pending JPH01113472U (en) | 1988-01-22 | 1988-01-22 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01113472U (en) |
-
1988
- 1988-01-22 JP JP698588U patent/JPH01113472U/ja active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2363400A1 (en) | System and method for inverting automatic gain control (agc) and soft limiting | |
| US4229707A (en) | Automatic gain control circuit | |
| US6078797A (en) | Method of controlling received signal level | |
| JPH01113472U (en) | ||
| CA1123065A (en) | Signal attenuator | |
| US3714579A (en) | Electronic volume and on/off circuits for remote control systems | |
| US4105976A (en) | Automatic gain control | |
| JP3328926B2 (en) | Television receiver | |
| JPS6223141Y2 (en) | ||
| JPS6345051Y2 (en) | ||
| JPS6233384Y2 (en) | ||
| KR910005617Y1 (en) | Volume regulating and mute automatic release circuit | |
| JPH0628826Y2 (en) | ALC amplifier circuit | |
| JPH0438134U (en) | ||
| GB2068188A (en) | Strong and weak signal receiving systems | |
| JPS6225016Y2 (en) | ||
| KR800001064Y1 (en) | Automatic gain control circuit | |
| JP3082922B2 (en) | Radio receiver | |
| JPH0265515A (en) | Level control circuit | |
| JPH0227631Y2 (en) | ||
| US3944930A (en) | Automatic change-over notification for a receiver | |
| JPS6143300Y2 (en) | ||
| JPS5924192Y2 (en) | Tuning accuracy setting device for automatic tuning circuit | |
| JPS63158033U (en) | ||
| JPS6314559B2 (en) |