Shock from USB printer cable

[Uwe Bonnes]

Keith Weisshar <keith.weisshar@verizon.net> wrote:
: There is even a slight buzzing sensation when rubbing a finger across the
: USB connection with just a very light touch and it goes away when the
: printer is unplugged. Have you had this happen with your printer?

: "petrus bitbyter" <p.kralt@reducespamforchello.nl> wrote in message
....
: > >> >> > > > > >> > is actually felt. It's not a standard 60hz shock like

Congratulation to Keith:

Top quoting 300 line up 9 levels deep to add some few lines....

Argh!

--
Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------

 

[Michael A. Covington]

"Keith Weisshar" <keith.weisshar@verizon.net> wrote in message
news:k5y2d.14013$W73.5795@trndny03...

There is even a slight buzzing sensation when rubbing a finger across the
USB connection with just a very light touch and it goes away when the
printer is unplugged. Have you had this happen with your printer?

This absolutely should not happen. There's not much difference between a
shock you can feel and a shock that can kill you. Either the power supply
is defective or the outlet that it's plugged into is miswired. (Probably
the former.)

We should no longer be discussing whether it is normal or safe. IT IS NOT.
We should be getting it fixed.

What I'm guessing is that in the printer power supply, there is leakage from
120V AC to ground, through a high enough resistance that all of the leakage
gets absorbed by the (correctly functioning) ground connection of the
computer when the two are connected together. There are also other
possibilities.

When Tech Support mentioned 10 mA they were probably talking about the
ability of USB ports to supply 5-volt power to other devices... completely
irrelevant.