Quote:
Originally Posted by Matt L
The problem isn't AC v. DC., but rather the voltage. 4KV will kill you instantly, 110V might not. AC allows high-voltage transmission using transformers at the load site. DC does not, so you need 110V transmission lines. That also means that you have to live no more than a few miles from the generator. Think of the cost of electricity if Edison's plan had won.
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If you assume that the human body has a constant resistance, then your explaination holds true. But if people get wet, sweaty, impaled by pointy electricified probes (current right into bloodstream)- the voltage required to draw .03Amps of current through your body goes down. (0.03A ? keep reading...)
The Navy taught me (I'm surprised you don't remember this Bot) that .03A is all that is required to end someone's life - which is why most cars and European (safety nazis come from Europe=) industrial equipment operate at 12 or 24v - If you only have 24v, over a Navy-assumed body resistance of 300ohm- (inter-post consistency fail), you will never get .03amps.
if I had a multimeter, I'd measure my resistance right now and post it up, but I'm at a Union plant and not allowed to carry one... =)
As to Bot's question - I think that the problem is too complex to define definitively- Rumors that I heard asid that getting shocked by AC will tend to make your muscles contract or jerk, and a DC shock will tend to make your muscles stay where they are. Obviously, the muscle jerk reaction will increase the chance that you dont keep touching what was shocking you, but I've been shocked by both 110VAC and 100VDC and while they felt different, I can't say that my arm muscles reacted any diffferently each time
I'm my opinion, both Ac and DC are equally capable of passing current through you and causing irreprable damage.
In the real world, sources of AC are usually at 110v (the wall outlet) and sources of DC are usually smaller (batteries, capacitors....). There is probably a "fault current capacity" arguement in there somewhere that says - the theoretical maximum current of a given battery is still less than the maximum current that can be delivered by a home/industrial AC circuit (before its breaker opens...) and like I parroted earlier, its the current that gets you. This last argument (which Is still my conjecture) flies in teh face of a car battery (which can instantaneously create a LOT of current and doesnt come with circuit breakers when installed)
Matt L - I'm not trying to e-thug on you, I'm sorry if my post comes across this way. Its also possible that the navy fed me crap for 6 years and the ET training that I based my conjecture on was flawed. Wouldn't be the first time that a military dude got fed crap =) If anyone has better facts, I'm open to hear them.
omg what a threadjack. back on topic - while we can make more efficient combustion-based engines, they stuff have to burn stuff, and therefore make CO and NOx's. No way around this (except nuclear power =)
-John