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:
Mar. 24, 1981
Filed:
May. 25, 1979
Applicant:
Inventors:
Maurice I Smith, Carnation, WA (US);
John D Gillen, Kirkland, WA (US);
Assignee:
Tone Commander Systems, Inc., Redmond, WA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ; H04M / ;
U.S. Cl.
CPC ...
179 / ; 179 / ;
Abstract
A single line hold circuit adapted for connection between the tip and ring leads of a telephone line. The circuit comprises impedance means for connection between the tip and ring leads, the impedance means including a semiconductor element having high and low impedance states, the impedance of the low impedance state being sufficiently small to maintain the telephone line in a hold condition. The circuit further comprises means for causing the semiconductor to be in its low impedance state following an interruption of a predetermined length of time in loop current. A double line hold circuit is also illustrated.