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).

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?

Please do not confuse Power Factor Correction (PFC) with power supply
efficiency. They are two separate items. PFC can be either active or
passive, but usually alters the highly capacitive input of SMPSs.

Google "PFC".