How is one volt defined?

Just curious about it.

Does every country have its own devices to calibrate one volt in meters?

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Reply to
Mr. Man-wai Chang
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Last time I looked into this, the volt was made at a manufacturing plant and somwhere along the line the batteries were put in, which generates the coulombs, that moves the wheels..

I can't tell you the average speed at 1Volt, 1 Amp per second, thats a little over me head.

Jamie

Reply to
M Philbrook

I supposed power plants worldwide have their standard meters, right? Do they calibrate electricity meters vigorously to avoid mistakes and mishaps?

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Reply to
Mr. Man-wai Chang

Above my pay rate.

is implemented using the Josephson effect for exact frequency-to-voltage conversion, combined with the caesium frequency standard.

For the Josephson constant, KJ = 2e/h (where e is the elementary charge and h is the Planck constant), the "conventional" value KJ-90 is used:

excited by microwave signals between 10 and 80 GHz (depending on the array design).[3] Empirically, several experiments have

shown that the method is independent of device design, material, measurement setup, etc., and no correction terms are required in a practical implementation.[4]

Mikek P.S. Here is a calibration unit, if your interested. See links across top of page.

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Reply to
amdx

Reams and reams and reams of information available from a simple Google search, and you have to ask here?

Start "National standards bodies" and go from there.

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Reply to
Tim Wescott

Specifically, a volt is defined as the EMF that releases one joule of energy if one coulomb of charge is allowed to move through it.

A coulomb is the amount of charge transferred when a current of one ampere flows for one second.

The ampere's official definition is complicated, it is the amount of current that when flowing through infinitely long parallel wires 1 meter apart produces a certain force between them.

Reply to
Michael Moroney

"metric"? :)

Well, was expecting a short answer. I did do my homework and it seemed that the answer is not trivial...

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Reply to
Mr. Man-wai Chang

It's mostly an eastern/western hemisphere thing, apart from Japan (100V) and Taiwan (120V). See .

Cheers

Phil Hobbs

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Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
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Reply to
Phil Hobbs

as one thousandth of a kV. Or a millionth of a MV.Yes, in USA they have

120 volt in houses compared to 230 V to the rest of the world.
Reply to
Tzortzakakis Dimitrios

Yes, and the USA have the lowest electrical safety standards of the world, equal to Pakistan and back street Bangla Desh.

No RCDs in the American homes. You have to wait until the 600A main fuse blows.

How many get killed every year in USA by electricity?

w.

Reply to
Helmut Wabnig

We call them GFDs. My house has them in all outlets near plumbing fixtures or other likely-grounded locations.

Fuse? We use circuit breakers. My house is wired 120-0-120 volts, with a dual 125 amp main breaker. Most outlets are 120, and a few, for big loads, are 240. We don't have a/c, which is the big load in most of the US. Our heat and clothes dryer and cooking are gas.

Getting hit by 120 volts is not nearly so dramatic as contacting 240. I do most wiring hot.

A little browsing suggests that there are about 51K electrical fires in the USA per year, with about 500 deaths.

The corresponding numbers in GB look like 37K and 250.

The population ratio is about 5:1.

It's mostly older buildings that have electrical fires. There is some horrendous ancient knob-and-tubing stuff in the attics of old Victorians around here.

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Reply to
John Larkin

very intersting!there are some homes here, too, with marble (!) distribution panels, that means a sheet of marble, with everything on it (splices, knob type, switches, fuses,and so on). The owners of the homes are stubborn against modernizing them, as it's a great expense.

Reply to
Tzortzakakis Dimitrios

Knob-and-tube is perfectly good as long as nobody futzes with it. Problem is, old houses tend to collect "informal" electrical and plumbing work.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

fascinating!of course you have different methods as most houses in USA are built of timber. Here the old system was iron tubes (iron not steel!) on the wall and small boxes, both junction and for plugs etc. also of iron. sometimes I come upon paper insulated cables! there are still many underground cables with paper insulation (both medium and low voltage).

Reply to
Tzortzakakis Dimitrios

we also don't have A/C although in Greece we have separate units in each room.We have a wood stove and 2 pellet stoves. The pellet stoves are fully computerized and automatic. In our holiday home in Vori we have a wood stove, a cassette fireplace and 3 A/C units. In my mother's holiday house central heating with an oil furnace and another yet cassette fireplace.Here most houses are single phase with a 35 A main fuse and 3

  • 10 mm^2 feed (#10). Sometimes 3 phase 3 * 35 A. My sister's which is very big has 3*50 A main fuses and all floors are wired 3 phase.GFCI breaker on each floor.New code means that every residence *and* corporate must have a 30mA GFCI breaker.
Reply to
Tzortzakakis Dimitrios

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