JPH0262844U - - Google Patents
Info
- Publication number
- JPH0262844U JPH0262844U JP14054188U JP14054188U JPH0262844U JP H0262844 U JPH0262844 U JP H0262844U JP 14054188 U JP14054188 U JP 14054188U JP 14054188 U JP14054188 U JP 14054188U JP H0262844 U JPH0262844 U JP H0262844U
- Authority
- JP
- Japan
- Prior art keywords
- gain control
- level
- detection signal
- tuner
- 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.)
- Pending
Links
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 claims description 3
- 238000001514 detection method Methods 0.000 claims 4
- 238000010586 diagram Methods 0.000 description 3
- 239000003990 capacitor Substances 0.000 description 1
Landscapes
- Control Of Amplification And Gain Control (AREA)
- Circuits Of Receivers In General (AREA)
Description
第１図は本考案回路を適用したチユーナの一実
施例の回路図、第２図はスイツチング回路のブロ
ツク図、第３図は第１図各部の信号の特性図であ
る。
２……高周波増幅器、７……利得制御信号発生
回路、８……ＡＭ検波器、１１……レベル検出器
、１２……スイツチング回路、２２……ダイオー
ド回路、Ｃ１……コンデンサ、Ｑ３……トランジ
スタ、Ｒ０〜Ｒ４……抵抗。
FIG. 1 is a circuit diagram of an embodiment of a tuner to which the circuit of the present invention is applied, FIG. 2 is a block diagram of a switching circuit, and FIG. 3 is a characteristic diagram of signals at various parts in FIG. 2...High frequency amplifier, 7...Gain control signal generation circuit, 8...AM detector, 11...Level detector, 12...Switching circuit, 22...Diode circuit, C1 ...Capacitor, Q3 ... ...Transistor, R0 to R4 ...Resistance.
Claims (1)
周波信号のレベルに応じて利得制御信号発生回路
で利得制御電圧を発生し、該利得制御電圧で少な
くとも該フロントエンドの高周波増幅器に供給し
てその利得を可変するチユーナの自動利得制御回
路において、 該中間周波信号を検波して得た検波信号を供給
され、該検波信号のレベルを検出するレベル検出
器と、 該レベル検出器の出力する検出信号に応じてス
イツチングを行なつて該利得制御信号発生回路の
調整用インピーダンスを可変し、該検波信号のレ
ベルが所定値以下のとき少なくとも該高周波増幅
器の利得の低下を阻止するスイツチング回路とを
有してなるチユーナの自動利得制御回路。[Claims for Utility Model Registration] A gain control signal generation circuit generates a gain control voltage according to the level of an intermediate frequency signal output from the front end of the tuner, and the gain control voltage is used to at least apply to a high frequency amplifier of the front end. The automatic gain control circuit of the tuner that supplies the intermediate frequency signal and varies its gain includes: a level detector that is supplied with a detection signal obtained by detecting the intermediate frequency signal and detects the level of the detection signal; A switching circuit that performs switching in accordance with an output detection signal to vary the adjustment impedance of the gain control signal generation circuit, and prevents at least a decrease in the gain of the high frequency amplifier when the level of the detection signal is below a predetermined value. An automatic gain control circuit for a tuner comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14054188U JPH0262844U (en) | 1988-10-28 | 1988-10-28 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14054188U JPH0262844U (en) | 1988-10-28 | 1988-10-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0262844U true JPH0262844U (en) | 1990-05-10 |
Family
ID=31404807
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14054188U Pending JPH0262844U (en) | 1988-10-28 | 1988-10-28 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0262844U (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5992627A (en) * | 1982-11-19 | 1984-05-28 | Pioneer Electronic Corp | Agc circuit of receiver |
| JPS6083428A (en) * | 1983-10-13 | 1985-05-11 | Fujitsu Ten Ltd | Automatic volume controller |
| JPS6035646B2 (en) * | 1981-06-27 | 1985-08-15 | 日本電信電話株式会社 | Manufacturing method of multi-fiber optical fiber connection terminal |
-
1988
- 1988-10-28 JP JP14054188U patent/JPH0262844U/ja active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6035646B2 (en) * | 1981-06-27 | 1985-08-15 | 日本電信電話株式会社 | Manufacturing method of multi-fiber optical fiber connection terminal |
| JPS5992627A (en) * | 1982-11-19 | 1984-05-28 | Pioneer Electronic Corp | Agc circuit of receiver |
| JPS6083428A (en) * | 1983-10-13 | 1985-05-11 | Fujitsu Ten Ltd | Automatic volume controller |