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:
Sep. 10, 1985
Filed:
Jul. 21, 1983
Pierre Albouy, Lannion, FR;
Abstract
The apparatus comprises a zero pass detector (2) for detecting zero passes in a voltage signal proportional to the line current to generate a pulse signal constituted by positive and negative rectangular pulses of equal amplitude and of width dependant on the duty ratio of the line signal, a pulse signal processor constituted by a saturable integrator circuit (4) connected to integrate the pulse signal and to deliver a triangular signal having a positive peak value which increases after ringing has been answered, a comparator (6) connected to compare the triangular signal with a positive reference voltage (+Vr) and to deliver a loop detected signal when the peak value reaches the reference value, the loop detected signal being applied to a bistable logic device (8) which serves to store the loop detected signal and to deliver an output signal from the apparatus based on the stored signal.