[Milsurplus] DC vs AC for power distribution

[Brooke Clarke]

Hi:

Modern Switching Mode Power Supplies that convert DC to DC at a different voltage behave very much like transformers.  
That's to say they have fairly low losses and just do the transformation.  Doing that at high voltages allows getting 
the benefit of lower IR loss.

Westinghouse was selling AC street lighting systems using AC generators and transformers as a competitor to Edison's DC 
systems.  The Westinghouse system could cover much more distance than Edison's DC system.  So when Tesla patented the AC 
motor it was natural for Tesla to license Westinghouse at $1 per watt of generator or motor capacity in royalties.  
Edison fought dirty to try and stop AC power including electrocuting caught pets and promoting the electric chair (and 
maybe burning down Tesla's lab).

It was the Niagara Falls electric system going for AC that turned the tide away from DC which at that time had nothing 
to transform the voltage up or down in an efficient manner.

Not far from my house there's capacitive loading of the AC to bring the power factor closer to 1 so that reactive 
current IX loss can be minimized (the electric utility can not bill for them).  See:
http://www.prc68.com/I/TelephonePoles.shtml#Fig_12
In the EU there are specs for the power factor of most electrical loads to save on the IX losses.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/Clarke4Congress.html


milsurplus-request at mailman.qth.net wrote:
> DC vs AC for power distribution