Receiving section of a telephone with suppression of interference upon switching on/off
US6690790B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 2000 |
| Grant date | Feb 10, 2004 |
| Priority date | — |
| Expiry date | May 10, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/6016
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A telephone receiving section having a final stage, an electroacoustic transducer having a first terminal connected to the ground of the circuit, a unit for controlling switching on/off, a source of a reference voltage, a switch that can adopt a first position or a second position in order to connect the second terminal of the transducer selectively, via a capacitor, to a reference-voltage terminal of the reference voltage source or to an output terminal of the final stage, respectively, and control means that respond to signals of the unit for controlling switching on/off in order to activate or to deactivate the final stage and the reference-voltage source and to operate the switch in accordance with a predetermined time program. The receiving section operates with the same immunity to disturbances as a fully balanced structure, even though the transducer is not connected between two balanced outputs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.