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

On 27 mei 2009, at 18:03, Peter Beckman wrote:

...

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.