|Re: Voltage converters vs. transformers|
Message #14 Posted by Andrés C. Rodríguez on 24 Mar 2007, 8:52 a.m.,
in response to message #10 by Vieira, L. C. (Brazil)
Hi Luiz, everybody!!
First of all, I apologize if my posting was not as complete or correct as it could have been. My main concern was to alert for possible damage to some of our beloved calculators because of the not-always-known difference between "electronic power converters" and "transformers". I felt time was running out, and something has to be posted in the shortest possible time.
I learned about this difference in a hard way some 30 years ago. I was connecting a (then) rare telephome answering machine (110 V based) in my "soon-to-be parents-in-law" home (220 V, as AC comes here). The salesperson included a power adaptor with the answering machine, but (oh!) it was not heavy at all!... Well, the machine worked for some ten minutes... but then we all heard a loud noise, and the smell of a burned electrolytic capacitor showed that something had went wrong.
I then realized a triac circuit was doing a not good enough "voltage conversion"...
End of story: Fortunately, I was able to put a new electrolytic in, fix the thing, connect a classical transformer, and the whole incident was over; as witnessed by the fact that we are about to celebrate our 24th wedding anniversary this year :-)
Regarding power systems, in Argentina we are supposed to have 220 V 50 Hz, and triphase systems are 380 V. Of course, these are rms, not peak values.
Our government here is trying to "manage" a large increment in the electric power demand, caused by a combined effect of politically-fixed prices, increased economic activity, and little long-term infrastructure planning (you may perceive my disagreement here). So it is very possible that, at this very same moment, we have something like 199.95 V and 48.7 Hz... You know, it is within the 10% range and the populace will not notice it. And the engineers out there have little influence for the upcoming elections. Sad.
One of these days they may decide to "manage" gravity...