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:
Oct. 20, 1987
Filed:
Aug. 09, 1985
Daniel Lynch, Jackson, NJ (US);
Steven B Perry, Highlands, NJ (US);
Keptel, Inc., Tinton Falls, NJ (US);
Abstract
An apparatus adapted to be coupled into a party telephone line for selecting a ringing signal transmitted on the line from among a plurality of possible coded ringing signals that could be transmitted on the line and for coupling the ringing signal to a telephone is disclosed. The apparatus comprises a rectifier coupled to the party line for providing a rectified ringing signal, a first switch having the rectified signal as an input for reversing the polarity of the rectified signal at selected times, a second switch coupled to the first switch for selecting either the rectified ringing signal or the ringing signal itself and a third switch coupled to the second switch for coupling the selected signal to a telephone coupled to the third switch. A control unit comprising a microprocessor is provided which evaluates the incoming ringing signal to determine its frequency and controls the first, second and third switches to route the ringing signal to the telephone if it is of the proper frequency after any necessary frequency conversion which is performed under control of the microprocessor. Frequency conversion is performed by appropriate control of the first switch coupled to the output of the rectifier.