Patent ID: 8629624

Claim:
A load control device for controlling the power delivered from an AC power source to an electrical load, the load control device comprising: a power converter for generating a DC bus voltage, the power converter comprising an inductor and a power switching device coupled to the inductor, such that the inductor is operable to charge when the power switching device is conductive and to discharge when the power switching device is non-conductive, the power switching device controlled to be conducive for an on time; a load control circuit receiving the bus voltage and adapted to be coupled to the electrical load for controlling the power delivered to load; and a control circuit operatively coupled to the load control circuit for controlling the power delivered to the lamp, the control circuit receiving a control signal representative of an instantaneous magnitude of an AC line voltage of the AC power source, the control circuit operatively coupled to the power switching device of the power converter for controlling the length of the on time; wherein the control circuit is operable to calculate an average input power of the load control device using the on time, the instantaneous magnitude of the AC line voltage, and an inductance of the inductor of the power converter.