On 2008-02-03, Stephen Robinson wrote:
Carl Byrns wrote:
"Stephen Robinson" wrote in message
...

[ ... ]

How will 48v kill people, except for causing a fire, which 12 v is quite
capable of doing that also.

Do you own an arc welder? Look at the open circuit voltage(should be on the
case somewhere). Now look at all the shock hazard warnings.

If you don't own an arc welder the open circuit voltage is usually around 48
volts and arc voltage is around 25 volts (sound familiar?) and at the right
amperage that is enough to kill you.

You need the VOLTAGE to to push the CURRENT in order to kill
someone(approx 30 mA).The human body is a very high resistance object,

No -- the human *skin* is a fairly high resistance object,
though it varies with perspiration, and emotional stress (among other
things). Remember that skin resistance is one of the parameters charted
by lie detectors.

If you have two small cuts or punctures (try pins in one finger
of each hand) as little as 6V is sufficient to stop the heart. This
bypasses the skin. And the needed current is not amps, but mA.

It may not kill immediately, but it can hold muscles contracted
causing you to hold onto the source of the current, so the heart will
fail in not too long a time. I know that I had a voltage of about 48
VDC with some AC on it get hold of me through a sharp corner of a heat
sink. I could not control the muscles of that arm to pull it clear.
The only way I got clear was to grasp the wrist with the other hand, and
yank it with the muscles of that hand.

which needs very high voltage to provide that current. 48v ain't gonna
be enough.

Try between wet sweaty palms and wet sweaty feet on concrete.
And DC is worse than AC, because it never reaches zero to let you get
control of the muscles for even a millisecond.

Enjoy,
DoN.

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