On Sun, 26 Apr 2009 02:20:26 -0700, pg wrote:

I just purchase a Silverstone Power Supply Unit (PSU) for my PC.

I am amaze with the PFC (Power Factor Correction) rating of over 0.96,
which, according to some indicators, means it's 96% efficient. (4%
wastage as heat).

As others have already pointed out, 0.96 power factor doesn't mean 96%
efficient.

Power factor does have a slight impact upon efficiency, as a low power
factor increases the energy wasted in the power lines, but this is small
compared to the energy actually used by the supply.

Since it's a new unit I dare not to open up the PSU to see what type
of electronics they are using.

So I post the question here ----

Can anyone tell me what type of Power Conversion Electronic Devices
they use in those high PFC rating PSU?

Active PFC involves using a boost converter whose current draw is
sinusoidal and in phase with the voltage.

For more detail than you probably wanted to know, see:

http://www.onsemi.com/pub_link/Collateral/HBD853-D.PDF