Patent · US Expired

Low power line selection circuit for a telephone

US6252957A · kind A · utility

33Cited by
22References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 7, 1998
Grant dateJun 26, 2001
Priority date
Expiry dateOct 7, 2018

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M1/71
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A line-powered circuit for connecting a telephone line to a telephone voice circuit comprised of a digital part and an analog part. The digital part is a logic circuit for generating a line connect signal that indicates a telephone line should be connected to the voice circuit. The power for operating the logic circuit is provided by the line voltage associated with the tip and ring leads of the telephone line. The analog part comprises a first switch means for connecting the voice circuit to the tip lead in response to the line connect signal, and a second switch means for connecting the voice circuit to a ring lead in response to the line connect signal.

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