On Oct 13, 7:16*am, Jules
wrote:
On Mon, 12 Oct 2009 19:35:40 -0700, Don Kelly wrote:
Well, I grew up in the UK, and it's been 240VAC as standard over there in
just about forever (well, near enough, Google tells me 1916) - although I
think some DC via private generation in big, isolated houses survived
into
the 1920's. The historical picture in the US is a lot more diverse, it
seems (and more interesting because of it :-)

The differences, both historical and current are fascinating from either
perspective. I've had some extensive discussions with an EE friend over in
Manchester and we're both learning something new all the time.

I don't think I've ever asked if there were ever DC rural systems over
there. These were off-grid and typically had a bank of lead-acid cells
which were charged by gasoline or steam driven generators or windmills..
There were 32V versions of virtually every small appliance of the day.
Radios, fans, food mixers, etc. They made sense when farmhouses were often
miles from the next house and *more miles to the nearest town.

And most *farmers were quite happy to tie to the grid when it became
possible - helping to build lines as well-- lots of rural electrification
co-operatives came into being in the late 40's.

Interesting stuff. I never knew they had any real off-grid networks; I'd
only ever heard of local generation supplying single dwellings. Shame
there doesn't seem to be much about all of this on the 'net.

The old windcharger/battery
systems worked reasonably well for supplying lighting and small
appliances but weren't capable of handling the heavier loads *around the
farms.

Take out the 'old' and that probably still stands

cheers

Jules- Hide quoted text -

- Show quoted text -

Edison went to great political lengths to discourage AC, even publicly
electrocuting animals to show how AC causes heart failure where the
equivalent DC voltage would not.

http://en.wikipedia.org/wiki/Topsy_(elephant)

As you know the very nature of DC required multiple grids and an
endless supply of local generating plants, all of which Edison wanted
to provide.

My relatives have a farm in central IL with a generating windmill,
this farm only got on the grid after WW2. In the 1930's windmill
manufacturers in the US were producing about 100,000 windmills a year
for farms that had no access to electrical grids. It used storage
batteries. Funny how the wind circle is now being repeated.