We’ve tried several times to explain the difference between the different type of UPS but it just gets too technical with diagrams and really boring text.
What we need is a demonstration, where you can see the effect of each of the different types of UPS. OK simple, what you need is an oscilloscope, some decoupling device, a variac, a multimeter. Oh, and of course one of each type of UPS.
Or you can have a look at this flash file on UPS operation. It’s cool!
UPS Operation Screenshot