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Invisible wrote:
> A0 paper.
>
> As in, the largest standardised paper size that exists, at more than a
> meter wide. (2.5 feet by 4 feet, roughly.)
>
(shorter_side)*SQRT(2).
--
Eero "Aero" Ahonen
http://www.zbxt.net
aer### [at] removethis zbxtnetinvalid
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Invisible wrote:
> scott wrote:
>>> (Woah - 63A? o_O Anybody know what thickness of copper it takes to
>>> handle that kind of currentl? That's gotta be more like a girder than
>>> a wire!)
>>
>> Roughly double your standard 13A cable would do... Look at the cable
>> going to the starter motor on your car, that's usually 100A or so.
>
> 1. A car runs on 12V electrics, not 250V. Does that make a difference?
No.
> 2. Is maximum load proportional to diameter or cross section area? (The
> latter is quadratically propertional to diameter.)
Cross section area.
(But I don't know how it is with really large
cross sections and currents.)
--
Tor Olav
http://subcube.com
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Invisible nous apporta ses lumieres en ce 2007/11/09 07:36:
> scott wrote:
>>> (Woah - 63A? o_O Anybody know what thickness of copper it takes to
>>> handle that kind of currentl? That's gotta be more like a girder than
>>> a wire!)
>>
>> Roughly double your standard 13A cable would do... Look at the cable
>> going to the starter motor on your car, that's usually 100A or so.
>
> 1. A car runs on 12V electrics, not 250V. Does that make a difference?
To my knowlege, only on the insulation.
The diameter of a cable is dictated the number of amps, it's insulation by the
volts.
>
> 2. Is maximum load proportional to diameter or cross section area? (The
> latter is quadratically propertional to diameter.)
Would be the cross section. But you have proportionatly less surface area to
evacuate any generated heat.
>
>> Can't you print it out tiled, ie 8 A3 sheets (or however many it is)
>> then just put them together?
>
> Well, in principle yes. In practice, I very much doubt you'd ever get
> the pieces to line up properly. (Ever notice how map books *always* put
> the place you want to look at in the crease?) Plus I'm having enough
> trouble finding somewhere to put an A3 printout without it getting
> crinkled up... :-S
>
> Apparently the planners have access to an A0 printer. I don't even want
> to imagine what that must cost... ;-)
The price is irrelevent when the equipment allows you to do your job. Also,
often, the highest priced options turns out to be the cheapest... in the long run.
Many mechanics can tell you: "I can't afford to buy any but the best tools
available, whatever the price!"
This is also true for engineiring firms.
--
Alain
-------------------------------------------------
You know you've been raytracing too long when you invented glasses that can be
configured to use variable resolution (eg. 320x240, 640x480, etc.), with POV-Ray
style switches for other effects (eg. anti-aliasing, radiosity, etc.)
Vimal N. Lad / Gautam N. Lad
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Alain wrote:
> The price is irrelevent when the equipment allows you to do your job.
> Also, often, the highest priced options turns out to be the cheapest...
> in the long run.
I wish somebody could explain this to the idiots I work for...
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> (Woah - 63A? o_O Anybody know what thickness of copper it takes to handle
> that kind of currentl? That's gotta be more like a girder than a wire!)
If it's less than 100 feet maybe #8? (~3 mm)
> 1. A car runs on 12V electrics, not 250V. Does that make a difference?
Yes, lots. Voltage is the size of the elephant, amperage is how fast he's
going when he runs you over. I think many cars will pull more than 100 A
cold starting though.
100 A * 12 V = 1200 W (~1.6 hp)
100 A * 220 V = 22 KW (~29.5 hp)
> 2. Is maximum load proportional to diameter or cross section area? (The
> latter is quadratically propertional to diameter.)
It's proportional to the surface area. Thus all the stranded and braided
wire.
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Tim Attwood wrote:
>> 2. Is maximum load proportional to diameter or cross section area? (The
>> latter is quadratically propertional to diameter.)
>
> It's proportional to the surface area. Thus all the stranded and braided
> wire.
Interesting. I thought braided wire was just so it bends without
fracturing...
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Orchid XP v7 nous apporta ses lumieres en ce 2007/11/10 04:11:
> Alain wrote:
>
>> The price is irrelevent when the equipment allows you to do your job.
>> Also, often, the highest priced options turns out to be the
>> cheapest... in the long run.
>
> I wish somebody could explain this to the idiots I work for...
You need to show them the operational cost the the lowest priced option compared
to that of the highest priced option. You also need to compare the quality of
the final product, and the amount of rejects with what those rejects cost.
--
Alain
-------------------------------------------------
You know you've been raytracing too long when you keep a blacklist of people who
ask questions about 3DFX products.
Alex McLeod a.k.a. Giant Robot Messiah
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Orchid XP v7 nous apporta ses lumieres en ce 2007/11/10 12:52:
> Tim Attwood wrote:
>
>>> 2. Is maximum load proportional to diameter or cross section area?
>>> (The latter is quadratically propertional to diameter.)
>>
>> It's proportional to the surface area. Thus all the stranded and
>> braided wire.
>
> Interesting. I thought braided wire was just so it bends without
> fracturing...
A solid wire have a smaler cross section than a braided or stranded wire of the
same caliber, but will be stiffer. In a braided wire, there are gaps between the
strands, and those make the cable whider.
So, yes, braided wires are needed when you need a supple wire, like that from a
socket to some device. But, a solid wire is beter in a wall, where it don't need
to change it's path once in place.
--
Alain
-------------------------------------------------
You know you've been raytracing too long when you hate games, but you buy Riven
just to look at the pictures.
AmaltheaJ5
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Alain wrote:
> Orchid XP v7 nous apporta ses lumieres en ce 2007/11/10 12:52:
>> Tim Attwood wrote:
>>
>>>> 2. Is maximum load proportional to diameter or cross section area?
>>>> (The latter is quadratically propertional to diameter.)
>>>
>>> It's proportional to the surface area. Thus all the stranded and
>>> braided wire.
>>
>> Interesting. I thought braided wire was just so it bends without
>> fracturing...
> A solid wire have a smaler cross section than a braided or stranded wire
> of the same caliber, but will be stiffer. In a braided wire, there are
> gaps between the strands, and those make the cable whider.
> So, yes, braided wires are needed when you need a supple wire, like that
> from a socket to some device. But, a solid wire is beter in a wall,
> where it don't need to change it's path once in place.
>
Adding to that, a braided wire might break, but there are enough cross
connections that under most circumstances you won't notice it.
Exceptions may be when connected to an amplifier. When I was young (or
at least younger) we had a, probably cheap, coax cable that connected a
guitar to an amplifier. If you shook it, you could here the 'water
sloshing' over the amp. Funny, but not very useful. Another occasion
was when connecting a bush of electrodes to a self made ecg amplifier,
those wires were long and shielded. Stepping on them would cause
something that superficially looks like a (part of) a ecg complex, about
the right amplitude and width. Very annoying if you are looking for
complexes with a different than standard morphology and have to press
the record button if you see one and the machine can not be used for a
minute after you did record that artefact.
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Tim Attwood wrote:
...
>> 2. Is maximum load proportional to diameter or cross section area? (The
>> latter is quadratically propertional to diameter.)
>
> It's proportional to the surface area. Thus all the stranded and braided
> wire.
No, this is not true for DC currents and AC currents at low frequencies.
(Maybe your are thinking about the "skin effect" that appears at high
frequencies ?)
Here's some relevant links:
http://www.ibiblio.org/obp/electricCircuits/DC/DC_12.html#xtocid183892
http://www.epanorama.net/documents/wiring/wire_resistance.html
http://www.interfacebus.com/Copper_Wire_AWG_SIze.html
--
Tor Olav
http://subcube.com
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