Wasn't the first frequency used in North America 25 HZ? At 25Hz, they could see the flicker in a ordinary light bulb and they used this to synchronies another generator when they wanted to supply more power to the line. Perhaps 50Hz came by just doubling 25 Hz. Now how did we get 60 Hz? > ---------- > From: Martin R. Green[SMTP:elimar@NOSPAMBIGFOOT.COM] > Sent: Wednesday, January 28, 1998 11:07 AM > To: PICLIST@MITVMA.MIT.EDU > Subject: [OT] Re: off topic > > I don't know why, but I do know it hasn't always been this way. Years > ago the standard voltage was 110V, then for some reason it was upped > to 112V, then 115V, then 117V, and now 120V. > > As for the frequency, many such decisions were completely arbitrary in > the early days of electricity. I do know it is easier to filter than > the 50Hz used in Europe and elsewhere, and allows slightly smaller > power transformers. My guess it relates more to available technology > at the time than through a conscious decision. The choice of a power > line frequency has affected the development of TV in the respective > countries as well, since the vertical refresh rate was chosen to match > the power line frequency to minimize interference. > > > CIAO - Martin. > > On Wed, 28 Jan 1998 07:07:36 -0800, richard dellacona > wrote: > > >hello out there does any one out there know why 60 cps and 120 vac > >is used in usa for line voltage no one seems to know or have a good > >answer for this question > > > Martin R. Green > elimar@NOSPAMbigfoot.com > > To reply, remove the NOSPAM from the return address. > Stamp out SPAM everywhere!!! >