Re: [CAD_CAM_EDM_DRO] Power Supply Safty

Wayne C. Gramlich wrote:

>In this discussion about Variac's (auto-transformers)
>and isolation transformers, I think some very vital
>information did not come to the surface.
>
>The key thing to understand is that electrocution can
>take place with a remarkably small amount of current
>through the heart:
>
> <http://www.rfcafe.com/references/electrical/electrocution.htm>
>
>That is right, 100ma applied across your heart would
>probably terminate your life.
>

Actually, it's worse than that. This is assuming that most of the
current flows
through the skin, and doesn't go deep. Supposedly, you can be electrocuted
by just a couple of mA (ie. 2 to 5) if the current enters through small cuts
in the skin. I've been shocked at least once through a cut by a low voltage
circuit that I know I would never have even felt with uncut skin.

And, there are a couple of famous electrocutions that ocurred with current
in the microamp range, through intra-cardiac electrodes, that required
extensive
changes in safety design and testing of medical equipment. If you've ever
poked around in hospitals, you will note that electrical plugs are clear, so
you can see the wires inside. But, there were a lot of other changes in
isolation
barriers inside the equipment to reduce stray currents especially in
connection to
electrodes or any other metal parts that touched the patient.

Jon