Patent · US Expired

Line current test device

US4912755A · kind A · utility

19Cited by
6References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 28, 1989
Grant dateMar 27, 1990
Priority date
Expiry dateAug 28, 2009

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04Q1/444
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A compact, unitary test device for use with telephone line conductors connected to customer premises telephone equipment comprises a first test circuit for terminating the conductors of the telephone line and for measuring current therein. The device also comprises a second test circuit for measuring current in the line conductors in series with the customer premises equipment during operation. A third test circuit provides a tone signal of a predetermined frequency to the line conductors. The test device has a switch set, a current measurement section, a resistance section, a tone generator and a power source. Further provided is a method of testing a telephone loop by measuring loop current level from a terminated position and in series with operative customer premises equipment. A tone signal is generated at a first predetermined point on the line conductors for reception at a second predetermined point.

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