> We just used Trace Engineering's classroom for Solar Energy
 > International's Photovoltaic Design and Installation workshop. So
 > Their sine wave inverters are slightly less efficient than their
 > modified square wave (marketing calls them modified sine wave)
 > inverters, but NOT 60%. The efficiency curve on the SW4024 never
 > goes below 85%.
Ian,
 I'm sure that Trace's stuff is better than what I have for UPSs. As you 
said, they even wind their own transformers in order to get higher 
efficiency. My units are meant for standby use, and first cost is much more 
important than efficiency while on battery power.
You might be able to answser this question: Can one of those big inverters 
(Trace, Heart, or ..??) be used as a standby power supply? I'm getting a 
BUNCH of computers here, most of which need to be on a UPS of some sort; I 
already have 2 1KVA and an 800 VA units, all of which run on 24 VDC. It'd be 
nice to replace them with one big UPS that would use my existing batteries.
Thanks!!                              >
--- FLAME v1.1
---------------