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Re: Wacky Weekend: NERC to relax power grid frequency strictures


From: Gary Wardell <gwardell () GWSystems co il>
Date: Sun, 26 Jun 2011 19:09:28 -0400

Hi,

Yes, transforming DC is not easy.

However, DC works good at long haul transmission because a lot of energy is lost in the revers EMF generated by AC a 
several hundred volts.  Some years ago a high voltage DC line was constructed between Oregon and California to deliver 
power to California.  The line converts to DC at one and and back to AC at the other.

Then again POTS phones have always used DC.

DC is commonly used in telecom equipment.

Well into the time of AC Portland, Oregon provided DC to the theater district for use in carbon arc lamps.

It might be noted that the 120v RMS at our wall outlets actuality has a peek value of 169.7 Volts from zero.  Or 339.5 
volts peek to peek.

Gary


Take a guess what the datacenter our equipment is currently hosted in uses.  Yet another reason to be glad of a 
datacenter move that's coming up.

Why can't we just all use DC and be happy?

motors don't produce DC?

dc generators produce dc.

tesla vs edison?

human safe dc voltage requires comically large conductors for the sorts of loads we energize?

transmission loss except at very high voltages...

http://en.wikipedia.org/wiki/High-voltage_direct_current

but transforming is not easy.
ac/ac transformers are easy tu build and very immune against lightning 
strikes - inverter systems are not.

Kind regards,
      Ingo Flaschberger






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