Robert, I do not recommend using an "online" UPS.
(An "online" UPS converts from AC to DC and back again.)
This is costly in terms of electricity (the conversion is inefficient) and is simply not necessary.
It is important, though, for a UPS to have a very low switchover time. Anything less than 1 cycle (8.33 mSec) is probably OK. 1mSec is very good.
I had a problem with a cheapie UPS, and it turned out to be the switchover time. My computer would reset every time.
I returned that unit, and purchased a Minuteman Enterprise series UPS. It has a 1mSec switchover time, and I have not had the problem. I like the fact that you can expand with external battery packs. These units are not cheap, but they are well-made, and less expensive than other competitive units.
Minuteman does also make online UPSs, if you insist.
If you really think you have a serious problem due to high-speed switching noise, or with noise coming in from the line, take a look at Filter Concepts. www.filterconcepts.com They make excellent filters - much better than the built-in filters, but also more costly. I use them, not because I had a problem with my computers per-se, but to cut-down the computer noise being picked-up by a shortware receiver.
(I use their SW series filters. These are their highest-attenuation filters. Probably unnecessary unless you are trying to kill radio noise. You have to wire these in. Take a look at the CF series, cord-connected filters, though. There are also cord-connected filters available in some of the other series, in the lower current ratings.) |
