Patent · US Expired

Line powered modem automatic answer device powered from equipment

US4415774A · kind A · utility

60Cited by
3References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 25, 1981
Grant dateNov 15, 1983
Priority date
Expiry dateNov 25, 2001

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M11/06
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

An automatic answering device controlled by attached data equipment and used with a modem powered from the telephone line. The modem and automatic answering device are automatically connected to and subsequently powered by the telephone line when a ring signal has occurred on the telephone line and the data equipment has indicated that it is ready to receive data. The energy needed to connect the modem to the telephone line is slowly accumulated from a data equipment over a period of time prior to the connection of the modem to the telephone line. The modem automatically hangs up when the local data equipment signals disconnect or the modem at the other end of the telephone line disconnects.

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