Telephone ringing extender

US4144408A · kind A · utility

Assignee

• Bell Telephone Laboratories, Inc. · US

Inventors

• Roger Edward Holtz · Indianapolis, US
• Bernard A. Tilson · Parsippany, US
• Gordon D. Woods · Denville, US

Key dates

• Filing date: Jan 30, 1978
• Grant date: Mar 13, 1979
• Expiry date: Jan 30, 1998

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04M19/006
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A telephone ringing extender is shown which includes a ringing signal detector and a switch. In response to ringing signals, the ringing extender grounds the tip conductor to operate telephone ringers bridged on the loop. Protection against excessive voltages and excessive currents is also provided.