Patent · US Expired

Three relay C. O. trunk interface

US4689816A · kind A · utility

5Cited by
7References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 15, 1985
Grant dateAug 25, 1987
Priority date
Expiry dateJan 15, 2005

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M7/0096
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

An interface system having a single detector to detect incoming signalling including ringing, tip ground, forward loop current, and reverse loop current. Relays and bias control are utilized to perform outgoing signalling and for configuring the system to defect the various incoming signalling states with a single detector.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.