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| Why isn't Alternating Currentu used to power Subways? (was R1/9 acceleration) (664318) | |||
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Why isn't Alternating Currentu used to power Subways? (was R1/9 acceleration) |
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Posted by JournalSquare-K-Car on Sun Aug 10 12:06:09 2008, in response to Re: R1/9 acceleration (Re: What is the mechanical condition of the Low V?), posted by Dan Lawrence on Sun Aug 10 11:49:09 2008. I see now, thanks. I bet that DC chopper control would allow you to run in low power for a while...unless the equiptment would overheat as well. However, i think the transformer system, like on GG-1s would allow you to run at low power for longer times because no resistors are involved, and transformers are more effective at dropping voltage without wasting energy as heat..So now i have questions... Why don't they use AC voltage to power subways? It is easier, and more efficient to control. SAy they use 600 volt AC. The peak voltage might have to be 750 or something, since you have to get the root mean square of the sine wave to get the average line voltage. And anyways, i don't think 750 volts is too high, PATCO uses it. Moscow metro uses 850 volts, i think, so why not use AC to power subways? |
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