SCADA (was Re: Help to identify a computer?)

[Sridhar Ayengar]

Bob Bradlee wrote:
> On Sat, 17 Feb 2007 20:48:33 -0800, Brent Hilpert wrote:
> 
>> Chuck Guzis wrote:
>>> coke-oven (producer) gas.  For some reason never made clear to me,
>>> one of the competing "standards" for AC distribution was 25Hz (both
>>> 50 and 110v).
> 
>> Didn't the 25 Hz stuff have it's origins in turn-of-the-century
>> electric-train/streetcar technology? ..such established systems then being
>> extended into residential/industrial use in some areas. There were a few
>> 30's-era radios made for 25Hz, distinguished by their oversize power transformers.
> 
> I remember commenting about the lightbulbs flickering in the NY subway and my dad tellling me that the 
> subway operated on 25 cycle. this was close to 50 years ago. I asume it has been upgraded by now.

I believe they use high-voltage fluorescent in the Subway now.

Peace...  Sridhar