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:
Aug. 04, 1998
Filed:
Jan. 16, 1997
Applicant:
Inventors:
John P Fairbanks, Sr, Sunnyvale, CA (US);
Scott M Fairbanks, Sunnyvale, CA (US);
Assignee:
VoiceWaves, Inc., Sunnyvale, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
379372 ; 379377 ; 379382 ; 379413 ;
Abstract
The invention provides a method for detecting a call progress tone on a pair of telephone conductors (the telephone line). The level of energy stored in an energy storage device is continually checked. When the level of energy of the energy storage device is below a threshold, the system couples the telephone line to an off-hook impedance. While coupled to the telephone line, the system charges the energy storage device using current drawn from the telephone line, and the system detects the presence of the call progress tone on the telephone line.