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Old 10-03-2010, 10:44 PM   #23 (permalink)
ConnClark
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Quote:
Originally Posted by NiHaoMike View Post
A 120kRPM, 8 pole alternator is only 8kHz. Common silicon steel would be quite lossy at those frequencies, but it can easily be handled with powdered iron or ferrite. Switching power supplies, the most common application of those magnetic materials, operate at tens to hundreds of kHz.
Ferrite and powdered iron cores won't hold at 100,000 rpm. Also high frequency switching supplies greater than 200K typically use a buck or boost topology where the current flow remains relatively constant and doesn't switch direction.
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