Static mat repair?

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Static mat repair?

Darwin, Keith
I have a static mat but the grounding wire has broken where it attaches
to the mat.  Can the wire be reattached by simply bolting it to the mat?
The mat has some holes in the corners.  It would be easy to put a bolt
through one of the holes and clamp the wire to the bolt.  Or does the
wire need to connect with some conductive substrate in the mat?
 
And where is the current limiting resistor, in the wrist strap or in the
static mat ground wire?
 
- Keith KD1E -
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Re: Static mat repair?

W0rw
Hi Keith,
A snap or bolt through the mat will fix it.
Some mats are homogeneous and some just have a conductive top layer.
The bolt through the mat will work for any type.
The 1 meg resistor goes from the mat to ground. Your
wrist strap should have it's own 1 megohm resistor to ground.
Watch out for those solder suckers, they can generate a lot of ESD.
You can test the my trying to pick up some little pith balls.
Use plastic popcorn crumbs. If it attracts them after you
use it, it is generating an ES Charge.
Paul  w0rw
NARTE ESD Engr
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Re: Static mat repair?

Stuart Rohre
In reply to this post by Darwin, Keith
I would get a brass flat washer and solder  the wire to it.  Then, clamp the
washer with the bolt.  Use a lock washer under the nut of the bolt and you
are good to go.

Stuart
K5KVH



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Re: Static mat repair?

Ian Stirling, G4ICV, AB2GR
In reply to this post by Darwin, Keith
On Wednesday 15 March 2006 10:28, Darwin, Keith wrote:
> I have a static mat

 I built my K2 and many digital designs and circuits
over the years, many of my own design.  I never used
static precautions and have never had a component
failure.
  I don't think there is a conspiracy to sell static
mats as much as there is to sell statins to lower
cholesterol for no proven reason.


Ian, G4ICV, AB2GR, K2 #4962,
 who refuses to take cholesterol tests.
--
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Re: Static mat repair?

Kurt Cramer
In reply to this post by Darwin, Keith
Ian,

You don't live in this desert with 75°F and a dew point of 8°F in
March. Every time I get out of an upholstered chair and touch a metal
object I draw a 1/4 inch spark.

73, Kurt


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Re: Static mat repair?

Gary Hvizdak
In reply to this post by Darwin, Keith
On Wednesday March 15th 2006 Ian wrote ...

    I built my K2 and many digital designs and circuits over the years, many
of my own design.  I never used static precautions and have never had a
component failure.

                                --- - - - ---

All,

    Many factors contribute to the risk of ESD damage, including:
o   Your work area, is your floor carpeted, wood, concrete, etc.?
o   Even your chair, is it covered with a synthetic material?
o   The relative humidity.
o   Clothing - cotton fabrics are best for minimizing static build-up.
o   The sensitivity of the devices you are working with.

    World-wide ESD damage costs the electronics industry roughly 6.5 percent
of revenues, which comes out to more than 84 billion dollars annually!

    See http://www.desco.com/eearticle_files/enhancingprofits.htm for lots
more on this subject.  (Below is just a tiny portion of the information you
will find on that page.)

73,
Gary, KI4GGX

                                --- - - - ---

    Independent consultants have found that ESD costs the average electronic
manufacturer 4 to 8 percent of total annual corporate revenues, depending on
product designs and device sensitivity.

    Internal studies in telecommunication and other electronic firms have
revealed losses equal to, or in excess of, 10 percent of annual revenues.

    At an estimated average impact of 6.5 percent of revenues, this means
the international electronics industry is losing in excess of $84 billion
(USD) every year based on production data from 1997 through 2001.

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Re: Static mat repair?

W0rw
In reply to this post by Darwin, Keith
i worked in a failure analysis lab and i can send you pictures of
semiconductors
that have been damaged by ESD.
Some can be latent and fail much later.
i have a bunch of cool Scanning Electron Microscope pictures.
Don't ignore what you can't feel.
Feeling static occurs at 2000V.
Its out there are you are the one that causes it...
Humidify your work area and stay grounded.
Paul  w0rw
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Re: Static mat repair?

michael taylor-3
On 3/18/06, [hidden email] <[hidden email]> wrote:
> Its out there are you are the one that causes it...
> Humidify your work area and stay grounded.

Paul, & others,

What protections would you recommend a hobbyist take to ensure
low/less risk of ESD in the usual home ham shack?

Grounded (with 1Megaohm resistance) wrist strap?
Anti-static bench mat?
Anti-static floor mat?
Anti-static shoes or shoe strap? (the shoes/socks combination I often
wear to work can cause a static spark when getting out of my car in
the winter)
100% cotton lab coat?

Normally in the summers I'm trying to dehumidify my work area,
although the winters it tends to be both cold and dry.

Thanks,
 Michael VE3TIX
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Re: Static mat repair?

W0rw
In reply to this post by Darwin, Keith
Hi Michael.
1. Keep the Humidity up as high as possible.
2. Keep your wrist strap on when handling your rig,
stay grounded and keep your ESD sensitive rig on the ground mat.
The most important thing is to stay at the same potential as your rig.
Touch the chassis of your rig before touching thing else on the rig.
Your movements are what causes static.
If you do that you will do well.
You don't need a ground mat for your feet if you have a grounded table mat
and a grounded wrist strap.
3. Go to www.esda.org and check out some of the training information.
Paul  w0rw
NARTE ESD Engr.
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RE: Static mat repair?

Ron D'Eau Claire-2
In reply to this post by michael taylor-3
Michael VE3TIX asked:

What protections would you recommend a hobbyist take to ensure low/less risk
of ESD in the usual home ham shack?

---------------------------------------------------

Here are the recommendations from Elecraft:

Preventing Electrostatic Discharge Damage

Your (kit) uses integrated circuits and transistors that can be
damaged by electrostatic discharge (ESD). Problems caused by ESD can
be difficult to troubleshoot because components may be degraded but still
operating, rather than fail completely.

To avoid such problems, simply touch an unpainted, grounded metal
surface before handling any such components and occasionally as you
build, especially after moving about.

For maximum protection, we recommend you take the following antistatic
precautions (listed in order of importance):

1. Leave ESD-sensitive parts in their antistatic packaging until you
install them. The packaging may be a special bag, other container
or the leads may be inserted in conductive foam.

2. Touch an unpainted metal ground before handling any sensitive
parts or wear a conductive wrist strap with a series 1 megohm
resistor. DO NOT attach yourself directly to a ground as this
poses a serious shock hazard.

3. Make sure your soldering iron has a grounded tip.

4. Use an antistatic mat on your work bench.

Check the first part of any Elecraft assembly manual for a host of good
information on successful kit building.

>From my experience, if you, as a minimum, use a grounded-tip soldering iron
and touch an unpainted metal ground regularly as you work, you'll be fine.
The mat and wrist strap are great for when you forget to touch the ground
regularly. I use them for just that reason.

I wince when I read about people using Styrofoam (TM) containers (egg
cartons, cups, etc.) for parts. While they won't hurt a resistor or a
capacitor, they can be huge static collectors. Just try to peel all those
Styrofoam peanuts off of your clothes once they jump out of the box!

Ron AC7AC

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