I just bought a new pair of Puma’s that have a natural rubber sole.
I also bought an electric repair kit from the 70’s. It was written in German so I can’t understand a thing. It included a five-foot, self-adhesive paper strip that was embedded with a flat strip of copper(metal that was copper in color). The idea is that you stick the self adhesive strip on your hand or arm, then run it through your shirt, down your pants, and larger matrix of the copper stuck to the sole of your shoe. I am pretty sure this would not protect you from electrocution, but may help with static electricity.
I have heard stories about rubber tires and natural rubber-soled shoes protecting people from electrocution. Is this true?
There are no insulators, just conductors with very high ammounts of resistance. Given enough current, rubber will be very happy to conduct electricity.
Rubber is perfectly good insulation for your typical household currents and such. I would WAG that the copper strip is for grounding; the theory being that if you get electricuted the current will ground through the strip, which is a better conductor than your body. (Electricity takes the path of least resistance.)
This is a gross oversimplification. I must assume friedo means there are no ideal insulators.
Latex and natural rubbers are indeed insulators, and before synthetic rubbers and plastics became common, latex and natural rubber were common insulators in packaging electrical components like tubes and capacitors.
However, they are not ideal insulators. Every insulator has a Breakdown Voltage, expressed in Volts per unit thickness, below which they act as insulators and pass no current. Above this voltage, though, the material permanently “breaks down” and changes chemically into a conductor, albeit a rather poor one.
Air is an insulator below 32kV/cm. Latex Linesmans’ gloves have a breakdown voltage between 1 and 30kV, depending on how thick they are and any chemical treatments or surface finishes they have. These are DC voltages.
Yes, breakdown voltages can vary with frequency, and above a few dozen Hz, capacitive effects begin to become unignorable.
So next question would be: which would break down into a poorly conductive chemical goo first, my skin or my new Puma’s? My money is on me, my skin rather.
Well, the whole object doesn’t melt down, just pathways through it, kinda like the way lightning bolts propagate in air.
But yes, skin has a high water and electrolyte content compared to cured latex, so your money is wisely wagered.
And a minor self correction – latex linesman’s gloves are probably rated at 60 Hz, not DC, since they’re used for working on potentially live powerlines.