Additional line coupling circuit to an intercom telephone set
US4504702A · kind A · utility
2Cited by
0References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1983 |
| Grant date | Mar 12, 1985 |
| Priority date | — |
| Expiry date | Jun 30, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/003
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An additional line coupling circuit to an intercom telephone set having inserted between the additional line and the intercom telephone set, a d.c. line uncoupling circuit as well as means coupled to one of the wires of the line for transmitting signals on the line and means connected to one or the other line wires for receiving the signals transmitted on the line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.