Isolated resistive signature detection for powered devices
US7643320B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2007 |
| Grant date | Jan 5, 2010 |
| Priority date | — |
| Expiry date | Feb 1, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/10
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In one embodiment, a load connected to power sourcing equipment (PSE) compatible with a Power over Ethernet (PoE) standard is characterized to determine whether the load corresponds to a valid powered device (PD). A switching signal having a first frequency is generated on the isolated side and used to generate an electrical current through the isolated-side primary coil of a power transformer in the PSE. A first voltage measurement, corresponding to a first line-side voltage across the transformer's secondary coil, is generated on the isolated side, e.g., using an isolated-side auxiliary transformer coil. The load is characterized based on the first voltage measurement and the first frequency. To compensate for voltage offset, a second voltage measurement can be generated corresponding to a second frequency of the switching signal, where the load is then characterized based on the first and second voltage measurements and frequencies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.