Line current protection circuit and method for linear and nonlinear hold circuit
US6778664B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2000 |
| Grant date | Aug 17, 2004 |
| Priority date | — |
| Expiry date | Mar 14, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A novel line-current protection circuit for detecting excessive line current from a telephone line and protecting line interface circuitry from the excessive line current is presented. The protection circuit is adapted to detect when an excessive current is present on the tip and ring lines indicative of the misconnection of the modem or other line interface device with a telephone network that presents an incompatible interface standard. The preferred embodiment appreciates the multimode hold current specifications throughout the world and evaluates the connection of the line interface circuit with a telephone line to determine the compatibility therewith. When excessive line current is detected, the line-protection circuit switches the vulnerable line interface out of the circuit. When compatible line current levels are detected, the present invention reconfigures the configurable hold circuit into its original operating (e.g., non-testing) state for call processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.