Protection against overvoltages of an interface of telephone lines
US6172864A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1997 |
| Grant date | Jan 9, 2001 |
| Priority date | — |
| Expiry date | Mar 18, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/18
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a system for protecting against overloads in a telephone system. The telephone system includes a telephone exchange, a ringing device and an interface, coupled to receive input signals on subscriber lines. The input signals are forwarded to either the telephone exchange or the ringing device depending upon the operating mode of the telephone system. The telephone line supplies a signal indicating the operating mode. A single protection device is coupled between the input of the subscriber lines and the interface. The protection device is controlled by the operating mode signal, and includes logic for protecting both the ringing device and the telephone exchange.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.