Telephone headset interface circuit
US5623544A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 17, 1993 |
| Grant date | Apr 22, 1997 |
| Priority date | — |
| Expiry date | May 17, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/51
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A telephone headset interface circuit is coupled to a telephone line to extract power for use by a headset amplifier and is particularly adapted for use with telephone handsets having dynamic or electret microphones. The telephone line connects a telephone to a service system, such as a Central Office, a PBX system, or a Key system. The interface circuit includes a power extraction circuit having a plurality of circuit portions, each one coupled to a corresponding one of the telephone line wires, so that substantially identical electrical impedance characteristics are introduced to each such wire. A ring suppress circuit, serially coupled between the power extraction circuit and the headset amplifier, senses the presence of a ringing voltage on the telephone line and decouples the power extraction circuit from the amplifier in response thereto.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.