Patent · US Expired

Subscriber circuit link interface for an automatic telephone exchange

US4752952A · kind A · utility

1Cited by
6References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 20, 1985
Grant dateJun 21, 1988
Priority date
Expiry dateMay 20, 2005

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M19/005
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

The interface of the invention comprises a power supply circuit (16) which is a symmetrical amplifier circuit, and a hybrid circuit (29) controlling the power supply circuit in DC and in AC. The hybrid includes a phase shifter circuit (44, 45) simulating long lines. Application: private telephony.

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