If you ever make how-to's, I'd love to learn. I have been collecting them in the hopes of one day using them. Can you explain how the power filtering works exactly? I can testify I have never had a problem while using one in over 20 years, but can't explain exactly how they clean the power.
One time, a battery died on my bedroom PC UPS. So, I plugged the PC directly to a wall until I could get around to replacing the battery. A month later, a surge blew my $250 power supply. That was the best PC power supply I ever bought, so I was bummed. I have never had a single PC component, power supply or otherwise, get damaged while on a UPS.
The grid power is REALLY screwed up sometimes, in a lot of ways...
Too may to recount all here, and I'm long winded!
While everyone was uber scared of power surges, brown-outs, low voltage is harder, and often chronic.
Depending on quality, some filter out the bad stuff, use capacitors to fill in the low power spots,
Others tear down the input power completely are reassemble it correctly, like a pure sine wave inverter.
If you can scrounge them low budget (like free) there is a LOT of fun stuff inside them.
When the battery dies, and being gel cells they all die, they still work as power filters, just no back-up capacity.
They also have phone line filters, remember plug in MODEMS & FAX machines?
If you have DSL that comes over the phone lines, the TrippLite brand backup had a better phone line filters than the phone company sent with the DSL kit, my sister is still using a salvaged TrippLite phone filter in rural Texas where the phone line was so lousy the DSL kit filter couldn't clean it up, but the TrippLite filter did, and 20 years later it's still working...
Noting like trying to get DSL when you can hear the neighbors conversations on a private line,
Remember, if you are rural, you are a 3rd rate, secondary market the phone company doesn't care about, so you gotta do what you gotta do...
Same with the power grid, live outside a major city, and you get power when they get around to it, or in my case they wanted $15,000 up front for a ground mount transformer nowhere but where I wanted to build the house,
And another $118,000 tacked on the bill for the next 20 years to pay for poles, wires, etc...
GREAT! A second mortgage before the first mortgage! (No thanks...)
Back when I used an old style (non-inverter) gas genny with an iffy (dirty) output I would plug a filtering UPS into the outlets to feed my sensitive electronics. On the back of these UPS's there is usually a few "filtered" receptacles and a few un-filtered ones. Most UPS's still need some sort of battery in it to filter, but it doesn't usually need to be a good battery for this purpose. A good UPS can take a modified sine wave from the genny and turn it into a pure sine wave. It will also stop any surges and spikes when the genny starts running rough...and if the battery is good it can also keep powering your loads while you re-fuel.
That's different, I've never seen one with unfiltered plugs.
The ones I've messed with, all were filtered, but only a couple were back-up powered.
