Questions about active power factor correction (PFC):
What is "power factor"?
Power factor, or “PF” for short, is the ratio of the real power used by a device, to the apparent power used by that device.
Real power is the capacity of the circuit for performing work in a
particular time and is measured in Watts. Apparent power is the product
of the voltage and current (V x A ÷ PF) of the circuit and is measured
in volt-amperage (or “VA”.) It is true that it sounds almost as if Watts
and VA are technically the same thing, and in DC they are (240W DC is
equal to 240VA DC, for example) but because energy stored in the load of
a device using alternating current (AC) is either returned to the
source, or has a distorted wave shape due to a non-linear load, the
apparent power can actually be greater than the real power. This would
give you a power factor of less than 1. Power factor below .70 is
generally considered poor power factor.
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