Patent · US Expired

Bi-directional signaling apparatus

US3999013A · kind A · utility

4Cited by
3References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 23, 1976
Grant dateDec 21, 1976
Priority date
Expiry dateFeb 23, 1996

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04Q1/38
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A solid-state sensor for use in the front end of a DX (Duplex) signaling unit to monitor signals on A and M leads and output signals on an E lead for transmission to a single frequency signaling unit (SFSU) or other E&M signal devices. This circuit replaces a polarized, bridge configured relay normally used for this application in communication circuits.

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