I couldn’t resist jumping in when I read a remark that the term
"high power" used with regard to coin shrinkage was “incorrect.” The
same remark went on to say that high current to push high voltage was
not high power.
This is not the case. Voltage is the push to current (Ohm’s Law).
Power includes a time element (power is simply energy released per
unit time), so very high voltage systems need only push small current
in a short time to yield high power. Now imagine a system that can
release very high current (pushed by high voltage) in a tiny fraction
of a second; the result is extremely high power, even if only for a
nanosecond. That pretty much is what happens in the coin shrinker.
they set up an experiment with massive copper cables attached to a
12 volt battery and the one who was on the betting side of 12 volts
wouldn't kill you held on to the cables then placed both arms in a
barral of brine. According to the story he dropped dead
immediately.
If both arms were in the same barrel of brine he would have probably
been fine but if there had been two barrels with an arm in each one
he probably would have been a goner. It is the passage of the current
through the heart muscle that kills you. It either stops or
interrupts the hearts rhythm and that is what is fatal. With both
arms in a single barrel of brine the brine would have been the path
of least resistance and the current would have flowed though it.
There are many apocryphal stories about folks being killed by
electricity and most are urban myth often used to try to impress some
lesson on safety. The current required to be fatal is a few milliamps
the voltage required is whatever it takes to drive that few milliamps
through your heart. It could be 1.5V or 1500V it all depends on the
circuits resistance; are you wet, is it salt water, do you have a cut
in your skin and many more factors that will determine the amount of
current flow at a given voltage. The relationship is given by Ohms
law I=E/R the current that flows in a circuit is equal to the voltage
in the circuit divided by the resistance in the circuit.
James Binnion @James_Binnion
James Binnion Metal Arts
The same remark went on to say that high current to push high
voltage was not high power.
I had a very strong feeling that I was wrong when I wrote that, and
even said so. And when I read it on the forum I saw my glaring
mistake with regards to current and voltage and which pushes which.
As I say I don’t understand this stuff and I never will. I should
have left well alone when being confused by the terminology rather
than opening up a can of worms. I seem to be very good at worm-can
opening if not physics!
So they set up an experiment with massive copper cables attached to
a 12 volt battery and the one who was on the betting side of 12
volts wouldn't kill you held on to the cables then placed both arms
in a barral of brine.
Ouch - I’ll NOT be trying that at home!
Rick, from reading of your various accidents, it seems that you have
more lives than the proverbial cat! You’re obviously made of strong
stuff!
I’ll be leaving electronics/electricity and all that stuff to the
experts as I don’t think I’ll ever get it. Mind you I think it’s my
stubborn gene coming into play. If there’s a subject (like physics)
that I can’t stand or that I find really boring, my brain absolutely
refuses to deal with it and understand it. Electricity falls into
that category.
