# Can someone explain power adapters to me?

**URL:** <https://boards.straightdope.com/t/can-someone-explain-power-adapters-to-me/387302>\
**Category:** Factual Questions\
**Created:** [January 9, 2007, 4:38pm UTC](https://boards.straightdope.com/t/can-someone-explain-power-adapters-to-me/387302 "2007-01-09T16:38:01Z")\
**Posts on this page:** 1\
**Page:** 3

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**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\
**Post date:** [January 18, 2007, 2:34am UTC](https://boards.straightdope.com/t/can-someone-explain-power-adapters-to-me/387302/41 "2007-01-18T02:34:30Z")

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[QUOTE=Crafter\_Man]  
I don’t know; perhaps a small amount.  
[/QUOTE]

Oh, they definitely do–at least the wall warts with a transformer inside. It’s called the no-load magnetizing (or excitation) current, and it’s due to various iron losses. Your typical small wall wart with a laminated silicon steel core will have an I[sub]x[/sub] of a few tens of milliamps.

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