The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 12, 1978
Filed:
Oct. 14, 1975
Glynn R Ashdown, Hawthorn Woods, IL (US);
Thomas McCartney, Deerfield, IL (US);
Bruce Holmes, Twickenman, GB;
Teradyne, Inc., Boston, MA (US);
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.