Justin The Cynical wrote: > Clark Martin wrote: >> Bruce Johnson wrote: >>> On Apr 29, 2009, at 6:58 PM, Paul wrote: >>> >>>> .I had been reading about how UPS's in general don't provide >>>> very good quality power in a blackout, >>> That's a very odd statement to make, since when running off of battery >>> UPS'es are providing as clean a power as you can get. >> If you are talking about a true UPS which outputs a sine wave that is >> true. Most UPSes produce what is called a modified sine wave and it is >> about as ugly as power gets. > > Splitting hairs a bit, but the term 'true UPS' (aka online UPS) refers > to how the power circuit is set up > (http://www.pcguide.com/ref/power/ext/ups/typesOnLine-c.html), not the > power output. I have a pair of APC SmartUPS units (1400 and a 1000) > that are not 'true UPS' units (they are line interactive) that output a > true sine wave, not the modified variety. A 'true UPS' /could/ output a > modified wave, but IMO, it's unlikely that the manufacture of the unit > would skimp on this due to the overall higher cost of this design.
Every true UPS I've seen outputs a sinewave. You're right that the two are not necessarily tied together. A true UPS really should always output a sinewave to avoid stressing devices that are plugged in and can only tolerate a modified sinewave for a short while such as transformer. Also a modified sinewave will tend to be noisier, both acoustically, when connected to transformers and electrically. This isn't terribly important during a power failure but it is when you are talking about operating 24/7 -- Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting "I'm a designated driver on the Information Super Highway" --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
