Volts vs Amps

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Strathead said:
I don't know why someone hasn't stepped up and insisted that conductance is required, as it is every bit as important as voltage, but still neither of those is what stops a person heart.
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Conductance gives you the same information as does resistance. Just in different terms.

Conductance = 1/resistance.

I guess electrical folks prefer speaking in terms of resistance.
 
jumper said:
Yep, conductance is rarely used, I cannot think of anytime outside learning Smith charts that I have ever used it.
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But we are so good at splitting hairs here:p as what is is, 12 pages of comments prove, that conductance, and not resistance is on the exact same level as voltage in its contribution to causing electrocution death. Which is none.
 
Strathead said:
But we are so good at splitting hairs here:p as what is is, 12 pages of comments prove, that conductance, and not resistance is on the exact same level as voltage in its contribution to causing electrocution death. Which is none.
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I am surprised that no one has brought up impedance. Is the body a pure resistive load? I will give you a clue as to what I think. I have a machine I check the clotting times of my blood with, as I am on blood thinning meds. The device checks the reactance of the blood sample to indicate INR (relative clotting time) of the sample without actually forming clots. At least that is what the tech guy at the company that makes the test machines told me.
 
Strathead said:
Silly I know, but then again, so is the entire premise of voltage.
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Voltage is a silly premise?

What is silly to me is fixating on current as if voltage did not exist. Current and voltage are different aspects of the same physical entity; you cannot have one without the other unless we are talking about superconductors. If you push current through a resistance, there is a voltage drop associated with it. Did the voltage or the current kill the subject? Yes.

This whole argument is silly.
 
Strathead said:
No, a better analogy to what I am referring to is a door knob in the winter. Infinite voltage is obviously (to me) a hypothetical theory, and it is likely that whatever stored to potential for a reaaaaaaaaaaaaaaalllllllllllyyyyyyyyyyy high voltage would also store enough energy for enough amperage flow to reach the 100ma threshold, but in theory, it doesn't have to. I read once that it takes approximately 12,000 volts to travel 1 inch. So a door know shocking you from 1/4 inch away probably hit you with 3,000 volts.
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And if that doorknob could somehow maintain its 3000V with you hanging onto it with a path back to the source through your body it would kill you dead. And you'll say that the only way that could happen is for enough current to be supplied to the doorknob that it can keep up with the current going through you back to the source. Yes, of course. Duh. But both the voltage and the current contributed to your unfortunate demise.

High voltage with very low current capacity won't kill you.
High current capacity with very low voltage won't kill you.
High voltage with high current capacity will kill you.

It really is that simple.
 
ggunn said:
Voltage is a silly premise?

What is silly to me is fixating on current as if voltage did not exist. Current and voltage are different aspects of the same physical entity; you cannot have one without the other unless we are talking about superconductors. If you push current through a resistance, there is a voltage drop associated with it. Did the voltage or the current kill the subject? Yes.

This whole argument is silly.
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The current killed. Wait, no, yup, it is still the current that killed.
 
ggunn said:
And if that doorknob could somehow maintain its 3000V with you hanging onto it with a path back to the source through your body it would kill you dead. And you'll say that the only way that could happen is for enough current to be supplied to the doorknob that it can keep up with the current going through you back to the source.
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No, I would say what I have been saying, the doorknob can't maintain 3000v and the 3000v didn't kill the person. Current is what stops the heart. It is as simple as that.
 
Strathead said:
The current killed. Wait, no, yup, it is still the current that killed.
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It's the electricity that killed. Electricity, all electricity, has voltage and current components; they are inseparable.

High voltage with very low current capacity won't kill you.
High current capacity with very low voltage won't kill you.
High voltage with high current capacity will kill you.

It really is that simple.
 
Strathead said:
No, I would say what I have been saying, the doorknob can't maintain 3000v and the 3000v didn't kill the person. Current is what stops the heart. It is as simple as that.
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And I said "if it could". It makes as much sense as what you have been saying.

High voltage with very low current capacity won't kill you.
High current capacity with very low voltage won't kill you.
High voltage with high current capacity will kill you.

It really is that simple.
 
ggunn said:
It's the electricity that killed. Electricity, all electricity, has voltage and current components; they are inseparable.

High voltage with very low current capacity won't kill you.
High current capacity with very low voltage won't kill you.
High voltage with high current capacity will kill you.

It really is that simple.
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You just lost all credibility with that statement. It is actually why I have continued to argue the point because this sort of misunderstanding is deadly. Regardless of the voltage, 100ma or more of current has the ability to kill you. I understand iWire's premise that current doesn't exist without voltage potential being present, but as I pointed out I feel this is a misnomer because voltage and current are present without a generator, but nobody is saying the the generator is what kills. But what you just said, is just plain dangerous thinking.
 
Strathead said:
You just lost all credibility with that statement. It is actually why I have continued to argue the point because this sort of misunderstanding is deadly. Regardless of the voltage, 100ma or more of current has the ability to kill you.
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Not without voltalge to overcome the resistance of the circuit.

So yes, if you stab a couple of probes through your skin to bypass a lot of the resistance a lower voltage can kill you.

IT STILL TAKES BOTH, it always has it alway will

Current cannot exist without voltage so it has to be both.
 
Just something to toss into the fire.....

For example, if you have a charged sphere, and you make it rotate, the charge will be on the surface and by rotating the sphere you will have a current on the surface, but the voltage is the same in all surface. Also magnetization of materials can induce currents by the same way.

http://physics.stackexchange.com/questions/51875/current-without-voltage-and-voltage-without-current
 
iwire said:
Not without voltalge to overcome the resistance of the circuit.

So yes, if you stab a couple of probes through your skin to bypass a lot of the resistance a lower voltage can kill you.

IT STILL TAKES BOTH, it always has it alway will

Current cannot exist without voltage so it has to be both.
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Again I repeat, without a generator you don't have electricity, so the same argument could be made that it takes a generator. It also takes a living being. Without a living being you can't have electrocution. That still doesn't change the fact that current kills. There are other factors that are required, but the one and only absolute constant is the amount of current that it takes to kill. Not the size of the generator or the amount of voltage potential, or the type of being, or the amount of sweat on the person's hand, or the surface area of contact, or any of hundreds of other factors. Current kills.
 
K8MHZ said:
Just something to toss into the fire.....

For example, if you have a charged sphere, and you make it rotate, the charge will be on the surface and by rotating the sphere you will have a current on the surface, but the voltage is the same in all surface. Also magnetization of materials can induce currents by the same way.

http://physics.stackexchange.com/questions/51875/current-without-voltage-and-voltage-without-current
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Isn't magnetic induced EMF technically a kind of voltage? Even though it makes the electric field a nonconservative field.
 
The voltage is not simply something in a long list of 'must be present' in order for current to flow. Voltage _must_ be part of the injury process.

As I have said before, focusing on the current alone is a useful approximation simply because it appears that the level of injury is proportional to the current level, at least for many electric shock scenarios. Because the level of injury is correlated with the level of current flow, IMHO it is a reasonable shorthand to say that the current is causing the injury.

However a little thought will show that the above must be an approximate model. Most likely, different shocks of the same current but different voltage are in fact different, but that the effect of voltage is smaller than the effect of current...and with our current level of knowledge we can't really discern the magnitude of the voltage factor. Add to this the fact of physiological variation, and it might simply be that the voltage factor is smaller than the noise of different people responding differently to the same level of shock.

Just because the research has not teased out the relative importance of voltage level in determining shock injury does not mean that voltage is not a factor; just not a factor that we can usefully evaluate.

I can come up with two plausible examples where voltage level would make a difference given the same current level for a shock. These are just guesses, not known injury mechanisms:

For example, one mechanism of injury is disruption of electrochemical signaling in the heart. If you place electrodes right on the heart then a very low voltage will permit lots of current to flow and cause injury. But this voltage must be high enough to overcome the various electrochemical potentials (cell wall voltages and the like) involved. Perhaps with really good electrodes and a really low voltage, you could get 100mA to flow through the heart without actually flowing on nerves. (Likely, no, but plausible!)

On the other end of the spectrum, if you reach the point where thermal injury is a concern, then very clearly a higher voltage shock of the same current will deliver more power. In other words, if the injury is by cooking rather than confusing nerves, it seems to me that watts will be a more important factor than amps.

-Jon
 
Volts go through the wire core And Amps travel around the surface area. Like the difference in a poot and a fart. A shart on the other hand, being a short to ground.

Sent from my XT1585 using Tapatalk
 
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