3 ms·

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

by zkms 9y ago

> 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!

jacquesm 9y ago
Isn't that usually used just for ships and aircraft?
- jis 9y ago
  And old IBM computers!
  - deleted 9y ago
    [deleted]
  - wglb 9y ago
    With a motor-generator units in each rack frame. Also used by xerox/SDS computers
- tyingq 9y ago
  There's a fair amount of ground military equipment that uses 400Hz also. Radar, microwave radios, satcom, etc.