T i m wrote:
On Sun, 9 May 2021 01:16:27 -0700 (PDT), fred
wrote:
snip
I once had this problem with a car. Get out, close the door, and get nasty shock. I found two answers. (1) close the door using the window glass and (2) hold on to metal frame of door before putting foot to ground.
+1
3) Allow your passengers to get out first. ;-)
This latter may be of use to you
My old Sierra went though a phase of high levels of static buildup and
in that case it was down to the tyre compound (low carbon content)?
I used one of those semi conductive rubber straps bolted to the towbar
frame that used to 'fly' off the ground once moving (so didn't wear
out or make a noise) but would touch the ground (and so earthing the
car) when stopped. I think some people used light chain.
It did eventually wear short so might then only touch if you had some
extra weight onboard but it worked very well till then (and I would
certainly know when I had stopped with it clear of the ground).
I think that in ESD sensitive environments if they don't want the
restrictions of wrist bands I think I have seen a form of dangling
ankle strap on a semi-conductive mat ... that keeps the charge levels
low but allows freedom of movement.
I wonder if brian put some silver foil on his chair then joined that
to some dangling plug chain that touches the floor via a 10k resistor
(or whatever resistance is normal on such things)?
Cheers, T i m
You could treat the chair with this.
https://www.aclstaticide.com/product...-safety-shield
There's a different product for treating carpeting.
(I hate products you keep having to apply over and
over and over again.)
If you're making homemade ESD straps, the dissipation
resistor you want is in the 1 megohm to 22 megohm range.
The 1 megohm one is easier to verify occasionally
with your multimeter, that it's still working. The
purpose of the resistance value, is to reduce the
"peak current" discharged into any semiconductor junctions.
The 22 megohm value is the highest resistance
value commonly available at retail.
Paul