"Tom S" wrote in message
ink.net...
If anyone knows of more relevant newsgroups to post this to, we'd
appreciate the info.

We're trying to find an uninterruptible power supply (~1000VA or
more) for a quiet environment (residential living room). Which
means the unit must not have any fans, buzzing noises etc while it's
operating, and above all else, must have an option to disable any
audible alarms it might have.

The problem is that step-up converters are quite inefficient because of the
high currents involved. This means you tend to need a fan to keep the thing
cool.