[Milsurplus] Edison/Tesla battle finally ends in NYC.

[Bob Camp]

Hi

I seem to recall that certain of the NYC subways ran on 25 Hz power.  
You could tell which ones they were by the way the incandescent bulbs  
flickered.I believe they still generate 25 Hz at Niagara Falls for  
some large industrial customers. The same thing is true in the Panama  
Canal Zone.

In all these cases the common denominator is the cost to convert  
motors from 25 Hz to something else.

Bob



On Nov 22, 2007, at 4:29 PM, Radioman390 at cs.com wrote:

> Con Edison, the local electric utility has finally stopped  
> generating 120 VDC current for an older section of Manhattan. Edison  
> fought Nichola Tesla's invention of AC current with a vengeance. He  
> would have public demonstrations where AC was used to electrocute  
> animals after they survived a DC jolt. (Yes, animals were harmed in  
> this research).
>
> AC allowed step-up andd step-down transformers to make for easy long- 
> range distribution of power; whereas DC networks required motor/ 
> generator setups. (high voltage on long lines also have a lower  
> voltage drop because of Ohms Law, and recovering lost voltage can be  
> accomplished by a step-up transformer).
>
> NYC had for the longest time into the 60s, a second AC system of 25  
> Hz, which is why older radios have 25-60 Hz ratings. But DC only  
> radios are doomed.
>
> BTW, 400 Hz is used in aircraft beceause less iron is need in the  
> transformers than a 60 Hz design, saving weight.  
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