Patent · US Expired

Telephone subscriber loop test system

US4852145A · kind A · utility

23Cited by
6References
33Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 22, 1988
Grant dateJul 25, 1989
Priority date
Expiry dateJul 22, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M2203/058
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A method of locating faults in a telephone system including the steps of connecting antiparallel rectifying switches (ARS's ) that inhibit alternating current (A.C.) flow in one direction but not the other between subscriber equipment and respective telephone company lines, applying an A.C. test signal to a telephone company line and measuring a resulting signal, and determining whether a fault is on the telephone company line or customer equipment based upon the resulting signal. Also disclosed is an ARS that includes a first input and output, a second input and output, and paths between respective inputs and outputs providing low turn-on thresholds in one direction between respective inputs and outputs and high turn-on thresholds in the other direction, the directions of low and high being the same for both sets of inputs and outputs.

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