Line feed circuit including negative impedance circuit
US4532384A · kind A · utility
8Cited by
5References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 4, 1983 |
| Grant date | Jul 30, 1985 |
| Priority date | — |
| Expiry date | Feb 4, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/005
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Communication lines for example telephone loop circuits are typically terminated with line feed circuits such that d.c. and a.c. terminating impedances are dissimilar. The line feed circuit includes tip and ring feed resistors of similar ohmic values for supplying the communication line with energizing current. An a.c. terminating impedance of greater ohmic value than the d.c. terminating resistance is provided by a negative impedance circuit which is a.c. coupled across the communication line, in shunt with the feed resistors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.