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Randy Yates[_2_] Randy Yates[_2_] is offline
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Default Audio Precision System One Dual Domani Measuirement Systems

Sorry, a lot of that paste below was gibberish. Here's
the link:

osha.gov/Publications/osha3075.pdf

--Randy

Randy Yates writes:

"Johny B Good" writes:

On Sat, 28 Jan 2012 00:28:20 -0000, Dave Plowman (News)
wrote:

In article
,
wrote:
n Britain one may readily obtain a "site transformer" which will
give what is advertised as 110 volt balanced power. I haven't been
there in 20+ years, can any Brits tell me if that's really true or if
120, or more, or less, is actually common? They are used for electric
drills and whatnot outdoors. Vintage US gear works fine at 110, but
mostly not current stuff.

110 volt via an isolating transformer is used on building sites etc for
all power tools. Purely for safety reasons.


Just for completeness ( I know I'm very late to this party but it's
an important point), Those 110v transformers produce a bi-phase supply
of 55-0-55 Vac. The two lives provide the 110v but the shock hazard
wrt grounding is reduced to a mere 55v which is merely very unpleasant
in the wet if the user happens to provide a path to earth.


Wrong. It's about current. Here's an excerpt from OSHA:


Below 1 milliampere Generally not perceptible
1 milliampere Faint tingle
5 milliamperes Slight shock felt; not painful but
disturbing. Average individual can
let go. Strong involuntary reactions
can lead to other injuries.
625 milliamperes (women) Painful shock, loss of muscular
control*
930 milliamperes (men) The freezing current or let-go
range.* Individual cannot let go,
but can be thrown away from the
circuit if extensor muscles are
stimulated.
50150 milliamperes Extreme pain, respiratory arrest,
severe muscular contractions.
Death is possible.
1,0004,300 milliamperes Rhythmic pumping action of
the heart ceases. Muscular
contraction and nerve damage
occur; death likely.
10,000 milliamperes Cardiac arrest, severe burns; death
probable


--
Randy Yates
DSP/Firmware Engineer
919-577-9882 (H)
919-720-2916 (C)