Whole house "battery" wiring/power...

[krw]

I already told you ,Darling Dufus, I don't do mops or work inside septic tanks. In particular, I don't want your job where they go together.

[krw]

You _are_ always wrong, just like ALwaysWrong. Are you related, just lovers, or perhaps both?

[The Daring Dufas]

How nice for you, neither do I. Try harder.

TDD

[krw]

But you have no choice. I understand; it's difficult for the mentally infirm to find employment.

[aemeijers]

So what does FLNF stand for? Google was clueless.

-- aem sends, slightly curious....

[krw]

Finger Lakes National Forrest? Who knows with the Darling Dufus.

[The Daring Dufas]

It's a shame you're in such bad shape. I'm sure there are some county or faith based organizations that could help you. Folks in your condition deserve at the very least a chance and a hand up.

TDD

[The Daring Dufas]

Funny Little Nose Fart, it's the sound you make when you laugh with your mouth closed. Then there is FLNFWSp, which is Funny Little Nose Fart With Spray. It happens when you see an intellectual post from krw and you have a mouthful of your preferred beverage.

TDD

[windcrest]

This could have been a very interesting thread if it were not for the few insecure nerds/geeks who think they have to prove something about their engineering prowess, and just wind up looking like a person with drastic insecurity issues.

I did however offer a marketable solution to your proposal, if you can find it somewhere in this mess.

Few others of these supposedly "illustrious" engineers actually offered anything worthwhile from what I can see.

Too bad.

[Jules]

For sure - it just stirred some braincells, that's all. The particular radio I remembered was an early (ish) transistor design - I think it may have been a Grundig, but I can't be certain now. The 12VDC ability was just to allow it to be run from a car battery whilst camping - I seem to recall my folks having a (black&white) TV that could run from a car battery, too, but I don't recall if it had a manual voltage switch like the radio did.

Just struck me as interesting that it was (in theory) so easy to plug in to AC (via the same connector) with the voltage on the wrong setting and presumably cook the thing!

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 :-)

cheers

Jules

[Stuart]

AC/DC radio sets were still commonly available into the 50s though, in the UK.

The Mullard valve amplifier circuits book, 2nd edition 1960, had a circuit for a 7W AC/DC amplifier, which was first published in 1957.

Stuart

[James Sweet]

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.

[Don Kelly]

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. My father was involved (from the utility side) with the the first one in Alberta, Canada, and the farmers were more than welcoming. 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.

[Jules]

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.

Take out the 'old' and that probably still stands ;)

cheers

Jules

[windcrest]

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.

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.

[Don Kelly]

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.

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.

These farmers weren't on any off- grid network. Some had windchargers and some may have had generators but many were still without electricity of any sort. Windmills to pump water, kerosene lamps. and wood or coal for heating. The co-operative effort was to get connected to the grid at a time when there were few, if any, farms remote from towns that did have grid connections. This meant building a local distribution system and the utility providing the tie to the grid and operation of the system. The first case was in a tightly connected Mennonite "colony" and later ones were more general groups of farmers after the success of this one. In general rural (and urban) population densities were (and still are) lower than those in IL(about 1/10 the population in 5 times the area-admittedly mostly concentrated in the lower half (prairie/parkland)of the province ).

[Don Kelly]

----- The sensitivity of humans and other mammals, with regard to frequency happens to peak in the 50-60Hz range. Edison took advantage of this and Tesla countered with high frequency, high voltage discharges, saying, in effect, "this is AC, perfectly safe" Both lied (whether they knew it or not and the not was shown much later) with profit as a motive. Other hazards such as arcing at switches or poor contacts, worse with DC, were ignored.

[Archimedes' Lever]

But he was wrong, and DC kills as well. Including the onset of ventricular fibrillation.

[Jules]

I recall the breakers at one site I was working at fed compressed air through the breaker upon opening, just to extinguish any arc that may have formed (that was a 400V DC setup) - I think that's typical on higher power DC stuff. The breakers were about the size of a lunchbox.

cheers

Jules

[daestrom]

Hi voltage AC breakers still do use compressed air in some. The 'blast' is aimed between the arcing contacts to literally blow out the arc.

Lower voltage DC (up to 350VDC) that we used on submarines just used blow-out coils to create a magnetic field that 'pushed' the arc-conducting gases up into chutes lined with alternating metal and insulating plates that would cool and stretch the arc.

But I've seen enough stuff that I know I haven't seen everything :-)

daestrom