JPH0266055U - - Google Patents
Info
- Publication number
- JPH0266055U JPH0266055U JP14632888U JP14632888U JPH0266055U JP H0266055 U JPH0266055 U JP H0266055U JP 14632888 U JP14632888 U JP 14632888U JP 14632888 U JP14632888 U JP 14632888U JP H0266055 U JPH0266055 U JP H0266055U
- Authority
- JP
- Japan
- Prior art keywords
- signal
- gain control
- bandpass filter
- specific frequency
- circuit
- 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
- 239000000284 extract Substances 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 2
Landscapes
- Facsimile Transmission Control (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Description
第１図はこの考案の一実施例によるトーン検出
回路の構成を示す回路図、第２図は従来のトーン
検出回路の構成を示す回路図である。
２……自動利得制御回路、３……バンドパスフ
イルタ、６……レベル判別回路。
FIG. 1 is a circuit diagram showing the configuration of a tone detection circuit according to an embodiment of this invention, and FIG. 2 is a circuit diagram showing the configuration of a conventional tone detection circuit. 2...Automatic gain control circuit, 3...Band pass filter, 6...Level discrimination circuit.
Claims (1)
ベル以上であるか否かを検出するトーン検出回路
において、前記入力信号から前記特定周波数の信
号を抽出するバンドパスフイルタと、前記バンド
パスフイルタの出力信号が供給される自動利得制
御回路と、前記自動利得制御回路における利得制
御信号のレベルが一定値以下か否かを検出する検
出手段とを具備してなるトーン検出回路。 A tone detection circuit that detects whether a signal of a specific frequency included in an input signal is at a certain level or higher, a bandpass filter that extracts the signal of the specific frequency from the input signal, and an output signal of the bandpass filter. 1. A tone detection circuit comprising: an automatic gain control circuit to which a gain control signal is supplied; and detection means for detecting whether the level of a gain control signal in the automatic gain control circuit is below a certain value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14632888U JPH0266055U (en) | 1988-11-09 | 1988-11-09 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14632888U JPH0266055U (en) | 1988-11-09 | 1988-11-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0266055U true JPH0266055U (en) | 1990-05-18 |
Family
ID=31415711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14632888U Pending JPH0266055U (en) | 1988-11-09 | 1988-11-09 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0266055U (en) |
-
1988
- 1988-11-09 JP JP14632888U patent/JPH0266055U/ja active Pending