Patent · US Expired

Automatic line defect detector

US5121420A · kind A · utility

23Cited by

1References

9Claims

0Family size

Assignee

Rolm Systems · US

Inventors

Michael R. Marr · Chapel Hill, US
Robert C. Boden · San Jose, US
Jakie B. Boyd · Santa Clara, US

Key dates

Filing date	Sep 17, 1990
Grant date	Jun 9, 1992
Priority date	—
Expiry date	Sep 17, 2010

Classification

Technology area (CPC H)Electricity
CPC primaryH04M3/30
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

Method and apparatus for detecting and sectionalizing troubles on telephone lines automatically. Specifically, an embodiment for detecting and sectionalizing troubles on a telephone line connecting a switching machine and a subscriber telephone set connected thereto over the telephone line, includes apparatus which: (a) emits a pulse over the telephone line; (b) detects reflections of the pulse; and (c) and determines whether a reflection was received prior to the expiration of a predetermined time period. The predetermined period relates to a distance which is less than the length of the telephone line between the switching machine and the subscriber telephone set.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.