Ed:

You are right - the first power generators were DC. One of the reasons
for Edison switching to AC, as I remember reading, was a marketing ploy!
It seems there were some early fatal accidents with high voltage DC
power and with lower voltage AC, it was suppose to be totally safe.
Edison did some public demonstrations that showed the safety of AC with
a goat or some other animal. Don't recall the reason for 60Hz choice.
I'll find that history book tonight and let you know.

- Wayne Foletta
BMI - Saratoga, CA
The Power of Quality

> ----------
> From:         Ed Koffeman[SMTP:edk@CYBERRAMP.NET]
> Reply To:     pic microcontroller discussion list
> Sent:         Thursday, January 29, 1998 2:17 PM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      Re: off topic
>
> >        Our system of 60 HZ line frequency may be based on a
> continuation
> >of the concept of time with 60 minutes in an hour, 60 seconds in a
> minute,
> >and 60 cycles per second.  It makes as much sense or as little sense
> as
> >anything else.
>
>
> As far as I know it was D.C. at first (Edison), and then Tesla had a
> lot to
> do (and George Westinghouse I think) with showing that A.C. was better
> because it could be transformed into high voltage/low current for
> lower
> losses and farther distances.
>
> In Ontario, Canada, the A.C. started out at 25 Hz, I believe. In the
> 50's
> the electric utilities paid for new motors (or to have them rewound)
> and
> transformers to do the big switch over to 60Hz.
>
> I didn't look this up just now, so I could be wrong about it.
>
> Ed Koffeman.
> Kinetra
> Brushless motor controls for R/C
>