Data station termination circuit
US4771449A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1986 |
| Grant date | Sep 13, 1988 |
| Priority date | — |
| Expiry date | Dec 1, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A data station termination circuit for connecting a four-wire, voice frequency transmission facility to either a four-wire or two-wire subscriber station in a telephone communication system for effecting a four-wire or two-wire mode of operation includes a gain/loss network coupled to a receive-in port for receiving incoming voice frequency data signals from a first signal transmission path of the four-wire transmission facility and for amplifying or attenuating the incoming voice frequency data signals. The gain/loss network is formed of a single operational amplifier, a set of binary weighted resistors, and a plurality of single-pole, single-throw slide switches. Other features disclosed include a battery back-up for use during a loopback condition and an optional equalization network for use in a second signal transmission path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.