[BenG]

If you have a model like the APC Smart UPS 700VA, couldn't you plug a couple of low current components into it, receive online power most of time, but when you wanted to listen, you could unplug the UPS from the wall and receive only battery power to your components(according to specs, you could get atleast a few hours of battery power) and therefore receive near perfect, sinewave power?

You would have to disable the audible alarm that sounds every 30 sec when the UPS is on battery power. How would go about doing that?

Thanks

 

[CaptBubba]

the alarm is probably a little pezio buzzer that could easily be taken out merely by locating it and de-soldering it.

I don't think that plan is something you want to go through with. Repeted use of batteries on a UPS will shorten the life of the UPS and the batterys. It may be best to go with a power conditioning unit, like the following lines from APC and triplite. It will get rid of the EMI and assored other junk and give you nominal AC voltage.

http://www.apc.com/products/Line-R/
http://www.tripplite.com/products/fa...ners/index.cfm

Or, if you want the get the king of them all, you could get something along these lines.
http://www.elect-spec.com/pwrcondiz.htm

 

[BenG]

The 700VA claims that it outputs a sinewave, but does not say if it only generates one when on battery power. I'm assuming that when the loads are receiving online power, the UPS is just passing along a slightly filterd and regulated AC current, which may be almost identical to what comes out of the wall. Right?

Sorry for the ignorance, but I'm trying to figure out these power units.