[geeks] New Intel Atom-based barebones system

Sandwich Maker adh at an.bradford.ma.us
Wed Aug 20 11:23:41 CDT 2008


" From: Jonathan Groll <lists at groll.co.za>
" 
" []
" 
" This wikipedia page:
" http://en.wikipedia.org/wiki/Switched-mode_power_supply
" 
" says: "An SMPS designed for AC input can often be run from a DC supply
" (for 230V AC this would be 330V DC), as the DC passes through the
" rectifier stage unchanged. It's however advisable to consult the
" manual before trying this, though most supplies are quite capable of
" such operation even though nothing is mentioned in the
" documentation. However, this type of use may be harmful to the
" rectifier stage as it will only utilize half of diodes in the
" rectifier for the full load. This may result in overheating of these
" components, and make them fail as shortcircuits"

otoh 330vdc means a lot less than half the current of 110vac, which
the diodes must be good for.  and the bridge is often on one large
heatsink, so you're only using half the diodes [with their thermal
impedance] but still have access to all the cooling.

and if you only ever plan to run the psu on dc, having the rectifier
fail short is kind of a non-issue.  you'd certainly be screwed if you
went back to ac though.
________________________________________________________________________
Andrew Hay                                  the genius nature
internet rambler                            is to see what all have seen
adh at an.bradford.ma.us                       and think what none thought



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