Why choose 120 volts?

Subject: Re: Why choose 120 volts?
Date: Thu, 28 May 2009 01:11:41 +0200

> I haven't seen a PC power supply which is incapable of both 120v/
> 60hz and
> 240v/50hz in a very long time.

After this nice voltage discussion, what about hertz? Would it be more
efficient for us Europeans to run our stuff at 60 Hz rather than 50? I
hear that a 50 Hz grid loses 15% more due to inefficiencies than a 60
Hz grid. Not sure if that also applies over short distances, though.

_Transformer_ losses are greater at lower frequencies. And the cores
have to be bigger.

That is the primary reason military avionics, and other onboard gear
use 400Hz AC.

Note: The U.S. as recently as immediate post WW-II had some areas of
25-Hz power. Transformer based equipment that was designed to be
"just adequate" for 60Hz mains was known to 'let the smoke out' when
plugged in in one of those 25Hz areas.