"Russ" wrote in message
...
Sure! I have a few of them. I usually get them for free because they
are "broken". I replace the batteries and they are as good as new. I
have even gotten a hold of an expensive "sine wave" UPS. Most UPSs
use a sum of square waves to simulate the 60Hz sine wave. There are
lots of transients and noise, however. Some (expensive) UPSs use a
different type of inverter and produce pure sine wave AC. If you put
an accessory plug in the side, you can use it to keep the batteries
topped off and plug into the accessory plug for volts. Be careful
though, the better ones use 2 12V batteries in series.

You need to be very careful with this - I have seen units that have one side
of line voltage on the battery terminals. This is not a problem with the
batteries sealed in the UPS, but could be a big problem if you try to bring
leads out to charge a battery.

I have about 25 UPS' I picked up at a local university sale for $30 total. The
largest was a 2KW unit with 18 12V batteries, one of which was dead :-).
Metalworking content - after replacing the one bad battery I tested it using my
bandsaw....

- Bob Headrick