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:
May. 29, 1979
Filed:
Aug. 16, 1978
Ellis K Cave, Garland, TX (US);
Dycon International, Inc., Dallas, TX (US);
Abstract
An automatic disconnect circuit is described for disconnecting a remote telephone in resonse to a hang-up click generated when the remote telephone goes on-hook. To distinguish a remote hang-up click from a local hang-up click, voice signals, and the like, all signals on the line are passed through a discriminator for attenuating high frequencies. Signals passing through the discriminator are sensed both as to their amplitude and their duration. Any such signal whose amplitude is too small results in no disconnect. Similarly, any such signal whose duration is atypical of a remote hang-up click results in no disconnect. Only a signal whose amplitude and duration are within predetermined limits, typical of a remote hang-up, causes the remote telephone to be disconnected.