steve:
a very well put together summeary.
I will use it for reference if i ever write an essay on the history of
electricity...something i've been wanting to do for a while.
73
Colin, V A6BKX
----- Original Message ----- 
From: "Ham Steve" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, April 27, 2006 12:47 PM
Subject: Historical Answer on U.S. versus Foreign Voltage


> In terms of power production - all power is the same. It is then
transmitted
> over High Voltage cables - usually above 10K Volts. The power is then
> stepped down before it reaches our homes.
>
> U.S, Japanese and some other countries receive 110V in the form of 2
wires -
> 1 Live and 1 Neutral (2 phase system)
>
> Other countries receive 2 live and in some cases 2 live in addition to 1
> neutral to create this 220-240V.
>
> Historically many countries originally used the 110V or 2 phase system.
>
> Some may argue that the US is behind or has just managed to stay afloat
with
> this old system longer.
>
> The only advantage to receveing 110V is less injury to the nervous system
in
> case of electric shock.
>
> The downside is due to more current to compensate for the power you are
more
> likely to get more burn (Yes skin burning) due to the 110V.
>
> The disadvantage of 110V as compared to 220V is more losses due to
> resistence. Higher current needed to compensate for lower voltage creates
> more heat and
> therefore more resistence in the system and thus the need for more power.
>
> The US is at 120 volts, not 110 volts. It was increased sometime around
the
> 1950s.
>
> The historic reason for 110 volts was due to the DC power systems created
by
> Thomas Edison. I think he chose 110 volts because that is what his light
> bulb
> worked on. Later on these systems were converted to AC so you didn't need
a
> power plant on every corner but the voltage wasn't changed so existing
> lighting
> didn't need to be replaced (they didn't care if they got AC or DC)
>
> An interesting question is why the rest of the world did _not_ wind up
using
> 110 volts. How did 220/230/240V get started over there?
>
> The US system theoretically could be made as good as (slightly better,
> actually) than the European system with no infrastructure change, except
to
> houses
> themselves. US houses get 240 volts at the panel. If wall outlets all were
> fed with 240V you'd have the lower current and higher power advantage of
the
> European system and it would be safer, since each "hot" would still be
only
> 120V from ground (not 240V) which keeps the reduced shock hazard
advantage.
> Of course it is still possible to touch the two hots.
>
> Don't worry about what people think; they don't do it very often.
>
> Steve, K8SP
>
>