Power supplies that convert alternating current (AC) to direct current (DC) may include front end Power Factor Correction (PFC) stage. The PFC stage may function in part as a resistive load to the AC power source, (e.g. the power grid). Some performance measurements of AC circuits may include power factor (PF) and total harmonic distortion (THD). PF is the ratio of actual electrical power dissipated by an AC circuit to the product of the root mean square (r.m.s.) values of current and voltage. PF indicates the amount of reactive power that does no useful work. THD comprises total voltage harmonic distortion (THDv) and total current harmonic distortion (THDi).