Quote:
Originally Posted by brit
Actually 0.5A is survivable - there's a weird effect of a sweet spot between 100-200mA that will send your heart crazy and kill you stone dead every single time, but up at 500mA and above the effect of your muscles is so severe that it can act to clamp the heart and stop it fibrillating. It will burn the hell out of you, knock you out and stop your breathing but you can just about survive it with medical attention  |
You are right that there are circumstantial cases of extreme electrocution that is survivable. I do know it largely is a matter of the current missing vital organs that is at play here, but I am not aware if the specifics of extreme severity of survivability in these cases.
Examples of survivability of high current is where the exit point is near the entry point, i.e. a bent elbow. This can (in rare cases) fry the lower arm, but not kill the person. On a limited scale a perfect example is putting you tongue to a 9V battery; you feel a serious tingle and the current is not insignificant, but little (if any) travels through your body.
I have personally witnessed a fellow engineering student getting stuck between a grounded antenna and a TV chassis for more than 5 seconds. Don't know the current nor the conductivity of the person, however, that was viewed as a miracle that he survived. ... It did ruin his day.
As a reference, by US electrical code (NFPA) a safe Ground Fault Circuit Interrupter (GFCI) activates at 5mA (0.005 Amp)
The example given earlier of a ring causing burns when touching a 12V source is not a matter of electrocution, but rather a "simple" burn from the heat/melting of the highly conductive ring. Short circuit a car battery with a standard wire and see it melt. There is no way touching a 12V source in it self can be of any harm.
BTW the definition of "low voltage" is 48 volts. In today's world that is the voltage that when touched will not allow enough current to be harmful. The original definition of 48 volts as being low voltage is more arbitrary. It is the voltage on a telephone line when the phone is ringing.
If you want to do a "mostly" safe experiment, rig up you land line phone so you can touch the wires and have someone call you. You will surely feel the tingle.