[PLUG] Thanks for the help Acer Laptop

[Galen Seitz]

Daniel Hedlund <daniel at digitree.org> wrote:

> Absolutely!  I had mentioned for the user to use a ammeter, but was
> probably foolish enough to mention the alternative which they could
> try if they were "stupid enough".  I probably should have added an
> additional warning explaining "why" I said "stupid enough ..."
> though. It's really about weighing risks.  The voltage that comes out
> of the power brick is DC 12-17v and thus doesn't oscillate near your
> heart rate, but the amperage (1-2.5amp) is sufficiently high enough
> that it definitely is no 9v battery either!  A wet tongue and the
> proximity between positive and negative make it less likely that it
> could kill you, but with an undiagnosed heart problem it is still
> possible.  I never thought to take in consideration that the power
> brick might exhibit excessive current such as if a resistor failed or
> a capacitor was overcharging itself; you have brought this to my
> attention as a valid possibility.  In my case, I've been stupid enough
> far too many times when an ammeter isn't handy, but I was willing to
> take that risk at the time.  For reference, what I originally
> recommended is below:

The real danger is from the possibility of the higher voltage from the
wall outlet leaking through the adapter.  This could happen due to poor
design or failing components.  Here's a good link:

http://www.allaboutcircuits.com/vol_1/chpt_3/4.html

and a quote from the link:

"In industry, 30 volts is generally considered to be a conservative
threshold value for dangerous voltage. The cautious person should regard
any voltage above 30 volts as threatening, not relying on normal body
resistance for protection against shock. That being said, it is still an
excellent idea to keep one's hands clean and dry, and remove all metal
jewelry when working around electricity. Even around lower voltages,
metal jewelry can present a hazard by conducting enough current to burn
the skin if brought into contact between two points in a circuit. Metal
rings, especially, have been the cause of more than a few burnt fingers
by bridging between points in a low-voltage, high-current circuit."

galen