Patent · US Expired

Impedance measurement in 4-wire to 2-wire converters

US4602338A · kind A · utility

29Cited by
5References
20Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 1, 1983
Grant dateJul 22, 1986
Priority date
Expiry dateSep 1, 2003

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M3/30
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

An oscillating input signal is applied to the 4-wire input terminals which is monitored while the 4-wire output terminals and the 2-wire terminals are also monitored. This procedure is performed with a first known reference impedance connected across the 2-wire terminals and then repeated with a second reference impedance similarly connected. A plurality of input frequencies may be applied over the range of 400 Hz to 4000 Hz.

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