US Patent 7787263 Methods and apparatus to control a digital power supply

Methods and apparatus to control a digital power supply are disclosed. An example method includes controlling a power factor controller by: receiving a first current signal flowing in a first stage of the power factor controller, receiving a second current signal flowing in a second stage of the power factor controller, determining a difference between the first current signal and the second current signal, determining if the magnitude of a measured current signal is above a predetermined threshold, activating an integrator to integrate the difference when the magnitude of the measured current signal is above a predetermined threshold, and outputting a first control signal and a second control signal to the power factor controller based on the output of the integrator.