According to Clever Monkey <spamtrap@clevermonkey.org.INVALID>:
[ ... ]
> I've been thinking of getting a small UPS for some time -- the power
> quality in Southwest Ontario has gone from bad to worse over the years,
> and we get brownouts all the time (which my boxes don't seem to notice),
> and actually 1-2 sec complete outages 1-2 times a week. I know I'm
> playing with fire with all the unclean shutdowns.
>
> I'd like to get a smaller unit that has a serial connection and works
> with NUT (or whatever) so I can shutdown cleanly on any outage that
> lasts over a few minutes.
[ ... ]
> Any recommendations? It is easy for me to get my hands on APC and
> Tripp-Lite stuff, but it is unclear from the NUT UPS compatibility page
> if the models I'm looking at will actually work.
Well -- what *I* really like are the ones which used to be
made by BEST. Incoming AC through a Sola type constant voltage
transformer (and a charging circuit which will keep the batteries up
full), and on a power outage, the thing switches over to an inverter
driving the CV transformer directly through other windings. It keeps a
pretty clean sine wave (compared to a lot of switching inverters), and
has excellent monitoring and control features. There is a companion
program (supplied in source format) called "checkups".
With checkups is a script to shut down the computer, and you can
tailor it to how long before battery empty status it will start the
shutdown procedure. So -- the script can shut the other systems down,
then shut itself down, and the UPS will go to standby to preserve some
battery life by limiting deep cycle discharges. When power returns, it
will all come back to life.
The only negative is that a CV transformer is somewhat
inefficient, so you get more heat in the computer room -- but you get
protected from brownouts and those annoying short outages. (Our short
outages seem to be related to trees blowing into the power distribution
lines, and tripping a breaker at the substation -- and it comes back on
in about three to five seconds.
Unfortunately, BEST got bought by someone else some time ago, so
you are limited to what you can find at hamfests, on eBay and other used
sources.
Mine is a 2KVA unit running from four heavy 12V gel cells, and
they seem to hold out for about five to six years before I need to
replace them -- and you replace all at the same time with matched
batteries, or you are asking for trouble
There are smaller BEST units, of course.
Best of luck,
DoN.
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