Date:         Tue, 12 Dec 1995 15:35:17 -0800
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         wabbott@mtest.teradyne.com (William Abbott)
Subject:      Soldering irons

	H2obxr writes:

>Also, there's voltage present at the tip of the soldering iron (if I remember
>correctly), so there's always the possibility of damaging sensitive
>components that are normally static sensitive.  I haven't tested the tip of
>my soldering iron personally, so don't know if this is true or not.

	Silly me, yes, you need to have a good quality Weller or similar
soldering station with a GROUNDED tip. There is indeed a voltage present-
0 Volts!!! :)  I hope that's what you're remembering!
	Cheap irons without ground wires, or irons with 'floating'
(not grounded) tips can indeed inject static into a circuit, but a
good iron shouldn't be a problem. If you wonder if your iron is grounded,
plug it in but don't turn it on, and just check continuity between
the tip and ground on the adjacent AC socket. If you iron hasn't
got a grounded plug, good bet it isn't grounded. You can check this with
the power off because the power switch doesn't affect the ground.
	If your iron has got a ground but no switch, check for continuity
from plug ground to tip.

	Remember that a small voltage may be present on many objects, 
Static damage isn't caused by 103mV picked up from your nearby AM radio
station or your cellular phone, though they may be source of static. The
static electricity that damages things is hundreds or thousands of volts,
at very small currents. You will NOT see a spark, or feel a shock,
when discharging this kind of static electricity, but it will trash
any exposed electronic components. (If you do manage to generate enough
to see or feel, you're gonna have mineature mushroom clouds inside
anything static sensitive that you touched...

	The trivial cure is to ground yourself and ground the item you're 
working on. A cold water pipe or the third (ground) lead in an AC 
recipticle works just fine. If you don't have either, drive a coppper stake 
into the ground (they corrode slowly), at least 6 feet, and keep the ground 
around it moist. Lay whatever you're working on on a pink polyethylene
or nickel-flashed bag or bubble-pack, or a sheet of aluminum foil, which
is itself grounded and connected to you. Don't have a groundstrap for you?
Keep one hand on the conductive mat at all times.

	Cheers!