JPS5564464A - Signal receiver - Google Patents
Signal receiverInfo
- Publication number
- JPS5564464A JPS5564464A JP13789278A JP13789278A JPS5564464A JP S5564464 A JPS5564464 A JP S5564464A JP 13789278 A JP13789278 A JP 13789278A JP 13789278 A JP13789278 A JP 13789278A JP S5564464 A JPS5564464 A JP S5564464A
- Authority
- JP
- Japan
- Prior art keywords
- maximum value
- level
- detected
- circuits
- 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.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/18—Electrical details
- H04Q1/30—Signalling arrangements; Manipulation of signalling currents
- H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
- H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
- H04Q1/46—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies comprising means for distinguishing between a signalling current of predetermined frequency and a complex current containing that frequency, e.g. speech current
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
PURPOSE:To attain echo protection of a multi-frequency signal receiver by a maximum value detection circuit which detects the maximum value of an input signal and a variable threshold circuit which varies the detection level of a limiter circuit in accordance with an output level. CONSTITUTION:Branching filter 2 separates an input multi-frequency signal into one wave each in higher and lower groups, which are applied to limiter circuits 3' and 3'' and maximum value detection circuits 7' and 7''. The maximum value of a one-wave component is inputted to following variable threshold circuits 8' and 8'' and compared there with minimum level VF to be received to make a check on whether it is a level to be detected; when it is the level to be detected, a threshold level damped from the previously-detected maximum value as much as required is applied to detection level terminal 9 of limitters 3' and 3'' and when not, VF is applied. If an echo component arrivers, the discharge time constant of the maximum value detection circuit is adequately set for prevention.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP53137892A JPS5831140B2 (en) | 1978-11-10 | 1978-11-10 | signal receiver |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP53137892A JPS5831140B2 (en) | 1978-11-10 | 1978-11-10 | signal receiver |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5564464A true JPS5564464A (en) | 1980-05-15 |
JPS5831140B2 JPS5831140B2 (en) | 1983-07-04 |
Family
ID=15209108
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP53137892A Expired JPS5831140B2 (en) | 1978-11-10 | 1978-11-10 | signal receiver |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5831140B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03171994A (en) * | 1989-11-30 | 1991-07-25 | Hitachi Ltd | Push-button dial signal receiving system |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0428768Y2 (en) * | 1985-03-26 | 1992-07-13 | ||
JPS61160937U (en) * | 1985-03-26 | 1986-10-06 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS52107708A (en) * | 1976-03-03 | 1977-09-09 | Northern Telecom Ltd | Method and device for translating multiple frequency signal |
JPS5471512A (en) * | 1977-11-17 | 1979-06-08 | Nec Corp | Receiver for multi-frequency signal |
-
1978
- 1978-11-10 JP JP53137892A patent/JPS5831140B2/en not_active Expired
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS52107708A (en) * | 1976-03-03 | 1977-09-09 | Northern Telecom Ltd | Method and device for translating multiple frequency signal |
JPS5471512A (en) * | 1977-11-17 | 1979-06-08 | Nec Corp | Receiver for multi-frequency signal |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03171994A (en) * | 1989-11-30 | 1991-07-25 | Hitachi Ltd | Push-button dial signal receiving system |
Also Published As
Publication number | Publication date |
---|---|
JPS5831140B2 (en) | 1983-07-04 |
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