Herbert Graf wrote:
>
> I used to think the same about computers but was quickly corrected. It seems
> that some computer supplies use diode capacitor multipliers in the first
> stage, meaning they would not function with DC, so you do have to be careful
> here too. TTYL

AFAIK this only applies to 120V mains equipment.
The rectified voltage of 230V~ is about 325V, the output of an active
power factor correction at 230V input is about 430V. To double that
would be too high for the used semiconductors.
But they actually double a 120V input voltage to get equal levels to
230V mains. It seems that the necessary current through the primary
semiconductors at 120V is a bit high and a voltage doubler to 240V makes
things easier. And of course you can sell the same power supply in 120V
and 230V countries by adding a simple small switch.

Other problems of using DC and not AC could be the active power
correction of high quality pc power supplies (it assumes sinusodial
input voltage to control current drawn from mains) and of course any
convential monitor degaussing (like another member of PICLIST mentioned
some time ago).

Florian

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