[LinuxUsers] Sine wave vs shaped square wave

[Jeff Lasman]

On Thursday 04 June 2009 08:34 am, Randall Whitman wrote:

> Anecdote: yesterday, in a power blip,
> my workstation, on APC Back-UPS ES 350, stayed up;
> employee workstation, on OptiUPS Voltage Stabilizer 1200 (Buck unlit,
> Normal mode green, Boost amber) rebooted.

Hmmm... check out the OptiUPS unit.

I've noticed a pattern over a few years.  My Smart-UPS 350s have 
occsionally failed and reported bad-battery after the fail though not 
before. Since this doesn't happen every time there's a power failure 
and since the unit which failed went through multiple "blips" (as you 
call them) yesterday, I think it's really a borderline not being 
properly noticed and reported by the system until it's "more" dead.

And this has repeated over the years I've had the unit; that's why I now 
use a much bigger one (sorry, no model number on the front and way too 
heavy to turn around and look at the back without better reason 
<smile>) to run my two desktop systems, one monitor, one switch, and 
even printer.

Since it's happened with more than one unit (all bought from the same 
factory-authorized rebuilder) I'm guessing it's just an old design that  
never worked well; I suppose it's time to buy new.  Rather than three 
small ones, I'm probably going to buy one big one, this time a Back-UPS 
with stepped square wave output but lots of features <smile>.

I've got everything back up now (the big unit has power to spare; it's 
got lots of indicator lights to tell me so):

Battery good: all six bars green

Load: only one third of maximum in use (two green bars out of six)

I'll do more within a week or three, so I have maximum staying power in 
case of failure, but I'm not worried today or tomorrow.

And that's a good thing.

Of course based on the article I linked to yesterday I'm wondering if 
the stepped square wave input is okay for the printer (HP OJ Pro 
L7680), but I'll read the UPS warranty carefully before buying; if they 
don't exclude printers from warranty, I'll buy that.

Jeff
-- 
Jeff Lasman, Nobaloney Internet Services
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