Open power loop detector for transmission line elements
US5438606A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 30, 1993 |
| Grant date | Aug 1, 1995 |
| Priority date | — |
| Expiry date | Apr 30, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/30
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An open power loop detector for digital transmission line elements using a pulsed, direct current test. The element detects when a fault in transmission lines has been corrected and the element should move from a loop powered mode back to a normal through powered mode. The detector includes a voltage regulator, voltage booster, current detector, and controller. The controller periodically activates the voltage booster to increase the direct current load between the transmit and receive cable pairs of the transmission lines. The current detector then senses whether a current is flowing between the center tap leads of the transmit cable pair. If no current is detected, indicating that the downstream transmission line still has a discontinuity, the controller waits a predetermined period of time before again activating the voltage booster and performing another test. When the current detector detects current during such a test, indicating that the cable incontinuity has been repaired, the controller moves the element to a through powered mode of operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.