IP telephone with power source circuit
US7079647B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 25, 2002 |
| Grant date | Jul 18, 2006 |
| Priority date | — |
| Expiry date | May 19, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/908
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An IP telephone has a power source circuit. A direct current from a network is used to charge an input capacitor via an input current limiting resistor. A resultantly charged voltage is inputted to and is converted by a DC/DC converter to produce an output voltage. In parallel with the input current limiting resistor, a limit removing unit including a switching transistor is arranged. The output voltage is delayed by a delay circuit to activate a driving transistor, which drives the switching transistor. The input voltage to the converter is monitored by an input voltage sensor. Therefore, the telephone power source circuit copes with a plurality of hubs of different power supplying specifications in an internet (IP) telephone network in which telephones are connected to a local-area network of the IEEE802.3 standard and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.