[GreenKeys] GreenKeys Digest, Vol 106, Issue 55

[John Nagle]

On 11/25/2012 7:23 PM, greenkeys-request at mailman.qth.net wrote:
> Date: Sun, 25 Nov 2012 14:17:18 +0000 (UTC)
> From: Keith Mc <acti at provide.net>

> But PLEASE remember: My ORIGINAL question was not asking WHAT
> people did, but *WHY* they chose a particular voltage or frequency 
> in the first place.
> 
> **BUT**   That doesn't explain WHY they chose "110V" in the first place!
> (vs 100, 130, or ANY other number)  Does anyone know?


   It's in Wikipedia.  Edison's carbon-filament lamps needed about
100V.  So DC generation was at 110V, to allow for some losses.
Tungsten lamps can be made in any voltage, but the original
carbonized paper lamp design had some inherent limitations.
(Early lamp manufacture also had the problem that the proper
voltage for each lamp varied over a range from about 90 to 130V.
Early production sorted the lamps, and the outliers were sent off
to isolated-plant applications that didn't have to run on a standard
voltage.  See "History of the Early Electrical Manufacturers",
published by the Harvard Business School, or "Men and Volts",
published by GE on their 50th anniversary.)
> 
> ... and why did many places choose (roughly) TWICE the voltage, 
> for mains?  

   See Wikipedia.

   Between 1983 and 2003, the European Union slowly moved line
voltages to 230VAC. Previously, line voltages in different EU
countries were 220V, 230V, or 240V.  The "Eurovolt" standard
made everyone in the EU run on 230V 50Hz.

				John Nagle