Quoting edcentric

MM, I have just gotten around to looking at the Fortron Blue thing.
There is something fishy about the rating.
They list 150W for 3.3 + 5. Sounds low.
and then for 3.3+5+12 they list 440W. It doesn't add up for me.

Welcome to the wonderful world of specifications. It's a challenge at times to determine what the "real" specs are. Try wrapping your head around stereo specs for a change.


Power Factor...hmmm...hopefully these snippets will help explain.

WHY IS POWER FACTOR IMPORTANT?

KVa is total power available to you and what you pay for. The lower the Power Factor, the more KVa is needed. Low Power Factors tend to make system voltage unstable, increase heat in electrical apparatus and can cause failure of electrical equipment. Many utility companies bill you for your poor Power Factor, increasing your cost of electricity. Utility companies have multiple rate schedules, and depending upon your rate schedule, Power Factor penalties may be a separate line item as a demand charge or may be considered as part your general electrical usage.


And now the marketing doctor's spin


Power factor correction sharply reduces the demand for reactive current which in turn saves fuel, reduces transmission and transformer losses, improves voltage regulation, and increases available capacity throughout the power company's system without additional investment in generation or distribution. Reducing peak current demand can allow the utility to postpone the construction of new generating capacity.


And I always said the PFC is best explained mathematically so ...Expand and bend your mind.