Patent ID: 7724831

Claim:
An apparatus for detecting load impedance in a transformer comprising: a transformer having a primary side and a secondary side, said transformer having a total current being sourced on said primary side, wherein said total current comprises a magnetizing inductance current component and a load current component; a first circuit component coupled to said secondary side of said transformer, said first circuit component differentially modulating load impedance on said secondary side of said transformer, wherein said differentially modulating said load impedance comprises: obtaining a data stream for communication from said secondary side to said primary side of said transformer; using a Manchester encoder to convert said data stream to a differential receive bitstream; and modulating said load impedance on said secondary side using said differential receive bitstream; and a second circuit coupled to said primary side of said transformer for detection of said modulated load impedance by differentially integrating said load current on said primary side of said transformer.