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> 60Hz commercial power, 40Hz LIRR power (Pennsylvania Railroad standard) 25Hz NYC Subway power, 700VDC Metro North power, 600VDC subway third rail power, and some old Edison 100VDC power.

The only thing missing is 400Hz power!

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Isn't that usually used just for ships and aircraft?

There's a fair amount of ground military equipment that uses 400Hz also. Radar, microwave radios, satcom, etc.

And old IBM computers!

With a motor-generator units in each rack frame. Also used by xerox/SDS computers

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