CH578810A5 - - Google Patents
Info
- Publication number
- CH578810A5 CH578810A5 CH932073A CH932073A CH578810A5 CH 578810 A5 CH578810 A5 CH 578810A5 CH 932073 A CH932073 A CH 932073A CH 932073 A CH932073 A CH 932073A CH 578810 A5 CH578810 A5 CH 578810A5
- Authority
- CH
- Switzerland
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H11/00—Networks using active elements
- H03H11/02—Multiple-port networks
- H03H11/04—Frequency selective two-port networks
- H03H11/12—Frequency selective two-port networks using amplifiers with feedback
- H03H11/1295—Parallel-T filters
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H11/00—Networks using active elements
- H03H11/02—Multiple-port networks
- H03H11/04—Frequency selective two-port networks
- H03H11/12—Frequency selective two-port networks using amplifiers with feedback
- H03H11/1217—Frequency selective two-port networks using amplifiers with feedback using a plurality of operational amplifiers
-
- 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)
- Amplifiers (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7223909A FR2191827A5 (US08080257-20111220-C00005.png) | 1972-06-27 | 1972-06-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CH578810A5 true CH578810A5 (US08080257-20111220-C00005.png) | 1976-08-13 |
Family
ID=9101217
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CH932073A CH578810A5 (US08080257-20111220-C00005.png) | 1972-06-27 | 1973-06-26 |
Country Status (9)
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2280141A1 (fr) * | 1974-07-26 | 1976-02-20 | Materiel Telephonique | Systeme de signalisation entre centres de traitement d'informations |
| US4313038A (en) * | 1978-10-13 | 1982-01-26 | Wescom, Inc. | DTMF Signal receiver |
| NL7903346A (nl) * | 1979-04-27 | 1980-10-29 | Bell Telephone Mfg | Digitaal signaleringsstelsel. |
| US4604755A (en) * | 1984-06-01 | 1986-08-05 | International Business Machines Corp. | Feed forward dual channel automatic level control for dual tone multi-frequency receivers |
| US5107491A (en) * | 1990-02-20 | 1992-04-21 | Advanced Micro Devices, Inc. | Collision filter |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3780230A (en) * | 1972-11-10 | 1973-12-18 | Bell Telephone Labor Inc | Multifrequency tone receiver |
-
1972
- 1972-06-27 FR FR7223909A patent/FR2191827A5/fr not_active Expired
-
1973
- 1973-06-06 IT IT50457/73A patent/IT985932B/it active
- 1973-06-07 BE BE132025A patent/BE800626A/xx unknown
- 1973-06-21 GB GB2948173A patent/GB1436623A/en not_active Expired
- 1973-06-25 SE SE7308900A patent/SE387033B/xx unknown
- 1973-06-26 US US373759A patent/US3909549A/en not_active Expired - Lifetime
- 1973-06-26 CH CH932073A patent/CH578810A5/xx not_active IP Right Cessation
- 1973-06-27 NL NL7308966A patent/NL7308966A/xx not_active Application Discontinuation
- 1973-06-27 DE DE2332696A patent/DE2332696A1/de not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| DE2332696A1 (de) | 1974-01-17 |
| SE387033B (sv) | 1976-08-23 |
| FR2191827A5 (US08080257-20111220-C00005.png) | 1974-02-01 |
| NL7308966A (US08080257-20111220-C00005.png) | 1974-01-02 |
| BE800626A (fr) | 1973-10-01 |
| US3909549A (en) | 1975-09-30 |
| IT985932B (it) | 1974-12-30 |
| GB1436623A (en) | 1976-05-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PL | Patent ceased |