Patent ID: 7616455

Claim:
A power convertor performing power factor correction comprising: a power conversion stage having an input side and an output side electrically isolated from each other across a boundary of isolation; and a control stage connected to said output side, said control stage comprising: a sensor for measuring an output electrical parameter of said output side; and a controller connected to said sensor and to said output side of said power conversion stage, said controller having accessibly stored a known relationship between said output electrical parameter and a corresponding input electrical parameter of said input side, said controller being operationally configured to generate a reference waveform indicative of a desired waveform for said output electrical parameter that achieves a desired waveform for said input electrical parameter based on said stored known relationship, said controller being further operationally configured to receive from said sensor a value indicative of said output electrical parameter, to generate a control signal based on a comparison of said value with said reference waveform, and to send said control signal back to said power conversion stage; wherein said power conversion stage is operationally configured to use said control signal received from said controller to modify said output electrical parameter and thereby condition said input electrical parameter and provide power factor correction based on said stored known relationship without measuring said input electrical parameter and using only parameters measured on said output side.