Solid state trunk circuit
US4776007A · kind A · utility
4Cited by
2References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 22, 1986 |
| Grant date | Oct 4, 1988 |
| Priority date | — |
| Expiry date | May 22, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M7/0096
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A trunk circuit is disclosed for coupling a bidirectional lead pair, such as balanced tip and ring leads, to a pair of unidirectional leads such as unbalanced input and output leads. The trunk circuit incorporates a small inexpensive transformer for effecting this coupling and for providing large common mode signal isolation and correct longitudinal balance. Circuitry is provided for matching the nominal balanced AC and DC line impedances. The trunk circuit also provides circuitry for generating dial pulse signals under control of a microprocessor or other external controller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.