On 10/13/2013 12:01 PM, Rob Doyle wrote:
  In general you can power 50 Hz equipment from 60 Hz.
But you have to be
 careful about powering 60 Hz equipment from 50 Hz - the transformer may
 saturate. Don't even think about powering 400 Hz equipment from 50 Hz or
 60 Hz. 
If the operating voltage is adjusted, you can actually use those things.
  I found that a 110V 25Hz induction-motor fan will run fine (but at
twice the speed) on 230V 60Hz.  Similarly, I used 115V 400Hz
transformers with 12V 60Hz power successfully.  Whether or not you can
find a 400Hz transformer with the proper turns ratio is another matter,
but I forget what I used mine for (could have been for a low-voltage
filament supply)--but it worked.
See, for example:
http://www.edn.com/design/components-and-packaging/4369085/Using-a-power-tr…
--Chuck