H04Q 5/245
Circuit arrangements in which for one subscriber low frequency speech and/or signalling
Official title: {Circuit arrangements in which for one subscriber low frequency speech and/or signalling signals proceed on the line, while for the other subscriber the low frequency speech and/or signalling signals are modulated upon a high frequency carrier signal}
H04Q5/245 (Circuit arrangements in which for one subscriber low frequency speech and/or signalling) appears on 5 US grants and 0 published applications in this corpus.
Search patents in H04Q- Granted patents
- 5
- Published applications
- 0
- Assignees
- 3
- Inventors
- 5
- Latest grant
- 24 Mar 1987
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 1 | 0 |
| 1978 | 1 | 0 |
| 1979 | 0 | 0 |
| 1980 | 1 | 0 |
| 1981 | 0 | 0 |
| 1982 | 0 | 0 |
| 1983 | 1 | 0 |
| 1984 | 0 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 1 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
- Single channel subscriber carrier system24 Mar 1987US 4,653,046 ABrand-Rex Company
- Interference limiting two-port network for 1+1 type transmission systems29 Nov 1983US 4,418,245 ACompagnie Industrielle des Telecommunications Cit-Alcatel
- Device for conveying a high-voltage low-frequency signal over a carrier connection8 Apr 1980US 4,197,433 ACompagnie Industrielle des Telecommunications Cit-Alcatel
- Variable delay ringing detector25 Jul 1978US 4,103,114 ABell Telephone Laboratories, Incorporated
- Battery charging circuit13 Sep 1977US 4,048,551 ABell Telephone Laboratories, Incorporated
No published applications in this class yet.
Most cited
By later US patents
- Battery charging circuit38US 4,048,551 ABell Telephone Laboratories, Incorporated · 1977
- Variable delay ringing detector2US 4,103,114 ABell Telephone Laboratories, Incorporated · 1978
- Device for conveying a high-voltage low-frequency signal over a carrier connection2US 4,197,433 ACompagnie Industrielle des Telecommunications Cit-Alcatel · 1980
- Interference limiting two-port network for 1+1 type transmission systems2US 4,418,245 ACompagnie Industrielle des Telecommunications Cit-Alcatel · 1983
- Single channel subscriber carrier system1US 4,653,046 ABrand-Rex Company · 1987