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:
Jun. 19, 1984
Filed:
Apr. 26, 1982
William T Cochran, Milford, CT (US);
International Telephone and Telegraph Corporation, New York, NY (US);
Abstract
The digital supervisory circuit comprises an amplitude comparator and EXCLUSIVE-OR gate to provide an output signal indicating the difference in time an input signal is above and below a predetermined reference potential. This output signal is integrated in an up-down binary counter and also is coupled to a first logic circuit under control of the counter which provides a ring present supervisory signal when a first threshold is exceeded and a second logic circuit under control of the counter which provides a switch hook detection supervisory signal when a second threshold is exceeded. A hit-timing circuit is provided coupled to the counter and the first and second logic circuits to prevent response of the counter and second logic circuit to line transients.