On Apr 26, 7:08*am, Sylvia Else wrote:
Sylvia Else wrote:
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?

Thank you all !!!

Something like this, perhaps

http://www.onsemi.com/pub_link/Collateral/NCP1653-D.PDF

Sylvia.

Hmm.... I wonder how those would handle an input in the form of a
"modified sine wave", which would more accurately be described as a
modified square wave, as typically produced by cheaper UPSs.

An ordinary PC PS wouldn't notice the difference.

Most power factor correction circuit will run on a rounded off square
wave without any trouble. In the short term, they watch the input
voltage and match the current to that. They don't make their own sine
function to match the current to.


Sylvia.