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View Full Version : Astonishing little AC/DC-adaptor


kuengb
Mar12-04, 01:42 PM
I have a question that maybe an engineer could answer. The voltage adaptor that came with my portable phone (Ericsson) in order to recharge its batteries made me wonder a lot. It is very small, about the size of a matchbox, and yet not much heavier. It's hard to believe that there's a coil with an iron core hidden inside, as in a standard voltage transformator. I also noticed that normal trafo's get warm simply if they're plugged in (and not in use) as a result of the ohm resistance (or whatever the word is) of the coil - this one doesn't.

Can anyone explain to me what technique is used here?

dduardo
Mar12-04, 02:14 PM
Based on this article:

http://www.elecdesign.com/Articles/Index.cfm?ArticleID=6185

They use a LTC1541 IC chip. Here are the specs:

http://www.linear.com/pdf/15412fas.pdf