Barry and Others,
Good suggestions. I have always wanted to take a antistatic bag and shake
coins, where only the coins were affected, and measure the response perhaps
out of the top of the bag. Then put a non-ESD bag with coins inside a
antistat bag, making sure in both cases that the coins hit
I just connected a wire of approx 30 cm (10) at the end of a 50 ohm coax
between core and shield) and plugged into
my Lecroy scope (1M) . I put a 10 dollar equivalent of Dutch money in a A4
PVC baggie and
shaked the coins up and down. The most amplitude i got was when i dropped
the bag in the
Hi Doug,
Can you give us detailed instruction for repeating your wonderful
experiment?
I tried jingling coins in front of some Anritsu measurement equipment. I
found no effect.
Thank you.
Barry Ma
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Original Text
From: Doug McKean dmck...@corp.auspex.com, on 3/18/99 1:40 PM:
On
Ok. Not as complex as I thought-in the TV! It sounds like simple RF
interference through the antenna. However, I have just tried shaking the
coins in a baggie at my computer monitor - nothing! Now at a 24 year old
TV on wire antennas in my basement. I got nothing at VHF frequencies (54MHz
to
It was 20 years ago, and now I live in a house without central heating and
cable TV , so I can not reproduct that effect.
But I remember for sure that the distortion similar to that which you get
from spark plugs of internal combustion engines, about half a TV scan line
long and repeating itself
Rene, That is an interesting phenomenon! If you could give me a more
detailed description of the TV distortion and black lines I might be
able to explain at least what was happening inside the TV set (I worked
many years in TV R D). This in turn might help others to explain what ESD
or EMI effect
George,
I think your reasoning is convincing to me. Thanks.
But please allow me to pose a silly question: Are we really sure those
kinds of shaking coins interferences can be categorized as ESD
(Electrostatic Discharge) problem?
In your experience, for instance, the screw driver did not carry
Do you get the same effect with the coins in a cloth bag or a paper bag?
Has anybody tried it?
Lou
At 10:57 AM 3/15/99 -0600, you wrote:
Douglas,
I have seen similar events in a different way. Years ago, I helped design
an electronic system using plastic chassis with nickel surface plating.
We might have to correct a misconception of triboeletrification that we
learnt from all demonstrations in schools. The myth is triboeletrification
only happens to insulators.
Can we try to say: Triboeletrification would cause transfer of electrons
between different materials. Insulators would
---Lou Gnecco l...@tempest-inc.com wrote:
Do you get the same effect with the coins in a cloth bag or a paper
bag?
Has anybody tried it?
Lou
To answer that, there are two parts;
1) Look at the triboelectric series chart. This chart, shows, what
materials when rubbed with what other
I remember a similar effect. Many years ago, when I was a student, in my
room I had a TV set with a simple loop antenna. 2 meters away from the
antenna was the radiator of the central heating of that house. On seams of
the elements of that radiator the paint had come off. Below the paint the
Barry,
Your question is very much justified. I use the word ESD because in my mind,
I
play the image of the striking screw driver in slow motion. If you imagine the
nickel surface robs the
screw driver of its electrons to charge up the screw driver, then the electric
field builds up as the
Lou,
It is impressive and my boss Doug Smith uses it during
some of his seminars. I have tried hitting the coins
in the bag with a hammer several times very near the
antenna - nothing. I even smacked two big screwdrivers
together on the metal near the antenna for several
minutes - nothing.
Doug,
Despite the sampling window, the spectrum analyzer has a wide open
front end. It is easily saturated by broadband signals, even though you
think you are only looking at say, 100 to 200 MHz, the front end amplifiers
see everything.
A lot of things have a piezoelectric effect,
I would recommend that Doug Smith of Auspex Systems
answer this one as he has presented this at an ANSI C63
ESD meeting and to the FAA.(He managed to crash their
computers)!!
Thank you
Charles Grasso
Advisory Engineer
StorageTek
2270Sth 88th Street
Louisville CO 80027 M/S 4247.
Tel:303-673-2908
There is an expanation for this seemingly unlikely event.
Having coins in a baggie and jingeling them causes the following
events to occur:
The rubbing of a coin against the polymer causes triboelectric
charging of both the coin and localized areas of the bag. Since there
are multiple coins,
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