Better Design for Computer Power Supplies?

[Steve Thomas]

The design of every computer switching power supply that I have seen
starts out with the mains power being rectified and fed directly to a
capacitor. This results in really bad power factor. I have a 230 watt
Startech brand which has an input current rating of 7 amperes at 120 volts,
and this is a typical example. I have never seen any attempt by any
manufacturer to improve this arrangement. Considering the number of these
supplies in use, we are certainly wasting a lot of power heating up the
wiring in our homes and offices.
Is anyone aware of any company that manufactures computer power supplies
with some attention paid to power factor?

--
Steve Thomas

 

[Richard Crowley]

"Steve Thomas" wrote ...

The design of every computer switching power
supply that I have see starts out with the mains
power being rectified and fed directly to a capacitor.
This results in really bad power factor. I have a 230
watt Startech brand which has an input current rating
of 7 amperes at 120 volts, and this is a typical example.

*Rating* or actual *draw*?

I've got 24 IBM NetVista PCs that have a nameplate rating
of 4A (which is what the electricians use to determine how
much power you "require".) However, in real-world, normal
operation, they draw less than 1A (by actual measurement.)

I presume that my "4A" rating (and your "7A") are the worst-
case, max-load, power-on, inrush ratings.

 

[CWatters]

Here are some with PFC...

http://www.endpcnoise.com/cgi-bin/e/nexus400.html
http://www.currentsolutions.com/search/ac_to_dc/pc-atx.htm

and some discussion on the advantages (not just efficiency)

http://www.overclockers.com/articles613/index02.asp


"Steve Thomas" <sthoma20lowspam@sympatico.ca> wrote in message
news:RmFAb.242$3y1.58890@news20.bellglobal.com...

The design of every computer switching power supply that I have seen
starts out with the mains power being rectified and fed directly to a
capacitor. This results in really bad power factor. I have a 230 watt
Startech brand which has an input current rating of 7 amperes at 120
volts,
and this is a typical example. I have never seen any attempt by any
manufacturer to improve this arrangement. Considering the number of these
supplies in use, we are certainly wasting a lot of power heating up the
wiring in our homes and offices.
Is anyone aware of any company that manufactures computer power
supplies
with some attention paid to power factor?

--
Steve Thomas