I have a transformer for my laptop, presumable output several volts. Whether charging or not, it warms up some of course from agitation of the ferrite domains, but not really hot. However, when I plug it from my APC brand UPS, I am quite sure it gets hotter than usual. The manual for the UPS states that output is a stepped-wave (square steps) approximation to sinusoidal output. Presumably that works OK in computers and most things, but I wonder: each of those sudden little jumps is a rapid dV/dt, and I figure that stresses and heats the transformer more than a sine wave. Think so? Heard or thought about this? The manufacturers don't warn about this. I think it could be degrading the transformer, because it gets very hot and I don't run it off the UPS anymore. I also wonder if transformer output is a nice sine wave, or shows distortion from stepped input. Could this type of voltage output from UPS be damaging equipment out there, and not appreciated?
- posted
20 years ago