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, 1987
Filed:
Nov. 06, 1985
Richard J Cubbison, Jr, Westminster, CO (US);
AT&T Information Systems, Inc., Holmdel, NJ (US);
Abstract
This invention relates to line circuits and, in particular, to the apparatus contained therein for switching the ringing signal on to the communication pair which connects the line circuit to the telephone station set which it serves. Electromechanical relays provide an ideal switching function but require a significant amount of space while semiconductor switches do not require much space but provide an imperfect switching function which adversely affects the performance characteristics of the line circuit. The subject ringing apparatus makes use of a semiconductor switch to provide the ring relay function and incorporates additional circuitry to eliminate the difficulties associated with semiconductor switches.