Patent ID: 7643320
Filing Date: 2010-01-05
Classification: H04L

Abstract:
1. A method for characterizing a load connected to power sourcing equipment (PSE) having a power transformer having (i) an isolated side with a primary coil and (ii) a line side with a secondary coil connected to the load, the method comprising: (a) generating, on the isolated side, a switching signal having a first frequency and used to generate an electrical current through the primary coil; (b) generating, on the isolated side, a first voltage measurement corresponding to a first line-side voltage across the secondary coil resulting from the electrical current provided to the primary coil; (c) characterizing the load based on the first voltage measurement and the first frequency; (d) generating the switching signal at a second frequency, different from the first frequency, to provide a different electrical current through the primary coil; and (e) generating, on the isolated side, a second voltage measurement corresponding to a second line-side voltage across the secondary coil resulting from the different electrical current provided to the primary coil, wherein the load is characterized based on the first and second voltage measurements and the first and second frequencies.