Testing electrically conductive lines to determine electrical characteristics thereof
US4113998A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1975 |
| Grant date | Sep 12, 1978 |
| Priority date | — |
| Expiry date | Oct 14, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/30
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A two-wired telephone testing system employing a low frequency test signal which is a submultiple of the power line frequency. This test signal is applied between the two-wires or between either wire at a point of potential reference (ground). A measure of the integrated value of the current between the connected points is then made for a period equal to one-half cycle of the applied signal with one polarity and one-half cycle with the polarity of the measured signal reversed. The integration periods are selected to be in phase with the applied signal for determining conductance and 90.degree. out of phase for determining susceptance. Direct current measurement can also be made for the same time periods.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.