Re: [CAD_CAM_EDM_DRO] Re: Gecko 5V supply

dave engvall wrote:

> I think 5 V is defined as being intrinsically safe
> or something like that.

No. 5 V (and up to 42 V nominal, about 60 V peak transient)
is the current figure for voltages that are safe to touch with bare
hands. But, it has to be current limited (actually energy limited)
to be considered Int. Safe. Fire alarm circuits, the old thick-wire
Ethernet tranceiver boxes, telephones (sort of) and a lot of other
stuff are at one level of int safe rating, because the energy source
will not deliver enough current to create a fire, even if one
component of the energy source fails.

I can guarantee 5 V is not safe just by voltage alone, as I've seen a
few fireworks shows when people got keyrings, hand tools or
scope probe ground leads in the wrong place, back in the days
of Schottky-TTL and ECL computers, with multi-hundred amp
power supplies.

Jon