Interface circuit interconnecting a bidirectional two-wire line with unidirectional four-wire lines
US4608464A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | May 1, 1984 |
| Grant date | Aug 26, 1986 |
| Priority date | — |
| Expiry date | May 1, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/23
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In an interface circuit which couples a two-wire line of bidirectional transmission and unidirectional four-wire receiving and transmitting lines; in order to permit the interface circuit to operate in adaptation to the fluctuation of an impedance with the two-wire line side viewed from the four-wire receiving line, the four-wire receiving line is provided with a plurality of filters and a group of switches for selecting the filters, an output of the four-wire transmitting line is compared with outputs obtained by scanning the filters, and the filter providing the minimum output difference in the comparisons is selected and connected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.