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On Wed, 7 Apr 2010 17:56:34 -0700 (PDT), wrote:

On Apr 7, 6:38Â*pm, wrote:
On Wed, 7 Apr 2010 12:31:47 +0000 (UTC), Jules Richardson

wrote:
On Tue, 06 Apr 2010 22:07:33 -0400, clare wrote:
As for safety - AC and DC are relatively Â* equal as far as shocks are
concerned - if Â*12 Â*volts DC does not give a shock, 12 volts Â*AC won't
either. Â*The only difference is Â*a Â*DC shock is a "single Â*hit" while AC
is a "buzzzz" WHich is more dangerous? Since Â*AC hurts more, I'd say DC
is the more dangerous - easier to ignore??????

Lots of old railroad engineers have told me that DC was far worse because
it can make muscles contract - and then you can't let go of whatever it
is that's causing the shock. Whether there's truth in that, I'm not
sure...

I don't know how many 240V AC shocks I've had over the years when I lived
in the UK, but certainly quite a few. I'm yet to get zapped by US
power... :-)

cheers

Jules

Â*The DC muscle contraction is true - when the current gets high enough
to cramp your muscles on AC it reverses and you have a chance to let
go -

How the hell can you have time to let go when the whole AC cycle is
1/60 of a second, the amount of time the voltage is close to zero,
being but a small fraction of that?

Muscle contraction is somewhat directional ? related to polarity and
with AC the contraction is not as strong and steady as with DC because
it is (a) interupted (b) reduced to RMS and possibly (c) reduced due
to palarity reversal

On DC it is Â*constant polarity and your muscle never relaxes.- Hide
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