How is an inverter different than a UPS?
A UPS typically includes the battery and battery charger in one stand alone unit. However, there are UPSs that use external batteries, and PowerStream makes inverters with battery chargers, so the differences blurr as features proliferate. UPSs also can have communication with the equipment that it is powering letting the equipment know that it is operating on standby, giving it shutdown warning, or communicating with the human in the loop. Inverters typically don’t have this communication. Q: Why are they called inverters? A: Originally converters were large rotating electromechanical devices. Essentially they combined a synchronous ac motor with a commutator so that the commutator reversed its connections to the ac line exactly twice per cycle. The results is ac-in dc-out. If you invert the connections to a converter you put dc in and get ac out. Hence an inverter is an inverted converter. For more information about such converters see http://www.nycsubway.org/tech/power/rotary.html
