Re: [PSES] ESD question

[Ken Javor]

Michael,

I downloaded those two articles from the In Compliance magazine web site. I
recall reading them at the time (2011) but I will re-read them with greater
attention.

Thank you,

Ken Javor
Phone: (256) 650-5261



From: "Wm. Michael King" 
Date: Wed, 20 Jun 2018 09:20:42 -0700
To: "Grasso, Charles" 
Cc: Ken Javor , "EMC-PSTC@LISTSERV.IEEE.ORG"

Subject: RE: [PSES] ESD question

Charles,
I've interacted with Ken on occasion through a LinkedIn EMC group. I see by
scrolling down through this thread that there are several components to the
conversation. As you have implied, I have a very rich and delineated history
of how this all started, and how it evolved over the decades since
approximately 1979 since much of it is based on my original research.

Since this appears to be involved with a ListServ, I have a simple
suggestion for anyone that might be interested in both the research and the
history. Please visit the web site of InCompliance Magazine. When there ask
for the archive under my name: W. Michael King. The majority of the ESD
details are there in a two-part serialized piece. Others are in posted on my
web site: systemsemc.com.

Thank you for the kind reference.

Michael

At 02:08 PM 6/19/2018, Grasso, Charles wrote:
> Ken,
>  
> The gun model is derived from extensive research by Mike King and others
> (David Pommerenke) to derive
> a pulse that reflects an ESD event from a human with an intervening metal
> object. 
>  
> I have copied Mike for his input. Dr Pommerenke is on the EMC blog.
>  
>  
> Thanks
>  
> Charles Grasso
> (w) 303-706-5467
>  
>  
>  
>  
> From: Ken Javor [ mailto:ken.ja...@emccompliance.com
> <mailto:ken.ja...@emccompliance.com> ]
> Sent: Tuesday, June 19, 2018 2:35 PM
> To: EMC-PSTC@LISTSERV.IEEE.ORG
> Subject: Re: [PSES] ESD question
>  
> 
>  This message originated outside of DISH and was sent by:
> owner-emc-p...@listserv.ieee.org
> What with Doug Smith being active in this sort of standard writing activity, I
> doubt it‚s simply inertia.
> 
> Ken Javor
> Phone: (256) 650-5261
> 
> 
> From: John Woodgate 
> Date: Tue, 19 Jun 2018 21:26:38 +0100
> To: Ken Javor < ken.ja...@emccompliance.com
> <mailto:ken.ja...@emccompliance.com> >, < EMC-PSTC@LISTSERV.IEEE.ORG
> <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> >
> Subject: Re: [PSES] ESD question
> 
>
> 
> Probably handed down on a stone tablet in 1910 and no-one had the courage to
> challenge it yet. (;-)
> 
>  
> John Woodgate OOO-Own Opinions Only
> J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> <
> http://www.woodjohn.uk <http://www.woodjohn.uk/> >
> Rayleigh, Essex UK
>  
> On 2018-06-19 21:18, Ken Javor wrote:
>  
>  
> ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model
> used in EN61000-4-2 and derivative standards? It seems it ought to be a human
> body model, but it isn't.
>  
>  Ken Javor
>  Phone: (256) 650-5261 -
>  
>  
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> 
>  
> 
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>  
> 
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>  
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Re: [PSES] ESD question

[Nyffenegger, Dave]

Wah???  You had to actually touch the TV to change the channel?

From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Wednesday, June 20, 2018 11:52 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question


It's probably not ethnicity directly, but skin resistance. This varies greatly 
between people. Long years ago, when we had touch-contact channel change on 
TVs, we had to double the sensitivity so that one particular person in the lab 
could work it. When we took sets to a show, someone turned up who couldn't work 
it.  We found it necessary to double the sensitivity again.  If you think about 
a person standing in the ESD field as a large (poorly-) conducting body, you 
can see why the effect can occur.

John Woodgate OOO-Own Opinions Only

J M Woodgate and Associates www.woodjohn.uk<http://www.woodjohn.uk>

Rayleigh, Essex UK
On 2018-06-20 14:06, Jim Hulbert wrote:
Somewhere, I have copies of the discharge waveforms (captured on a scope) from 
human subjects that Michael King recruited during his studies.  As I recall, 
the amplitude of the ESD pulses was limited to about 10kV as the subjects 
started to balk.

I believe Michael’s studies also led to the development of the Andy Hish 255 
probe.  The waveform from that probe, which was a long wand grasped in the 
hand, was influenced by the human body capacitance of the technician performing 
the tests.   There was a situation some years ago in our EMC Lab, where my 
associate and I both consistently passed a product for ESD using the Andy Hish 
probe, which was our corporate standard tester at the time.  However, an intern 
working with us consistently failed the product.  We did our best to make sure 
we were all following the exact same test technique.   The only difference my 
associate and I could think of was that the intern was of a different ethnicity 
than us.  We didn’t dare mention that, however.

Jim Hulbert



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Re: [PSES] ESD question

[Ken Javor]

I wouldn¹t lay claim to the mantle of ³great engineer,² but I have had a
very successful and fulfilling career, and greatly exceeded my expectations
going into the field.

While the names of my mentors might not mean much to most of you,  it is the
specific knowledge and skills I was able to access from each that is
important.

>From Bill Briles, who worked in aerospace and military aviation, I learned
empiricism, in a sense. That is, to learn a lot of the facts and sources and
to be able to quote chapter and verse on any topic of interest.  He was a
master of quoting any relevant military standard on just about any
electrical engineering topic.

>From H. David Fassburg, a radar systems and EMC engineer, I learned to think
about things and analyze them, not merely quote chapter and verse from some
authority. Both empirical knowledge and analytical skills are necessary.

And finally, from Mark Nave, five years my junior, I learned to look at EMC
engineering not only as a technical skill, but as a profession.  Mark Nave
ignited the desire to be in business for myself, and imparted some of the
skills and knowledge to do so (in addition to teaching me a great deal of
EMC design principles).

It also helped that at the same time Mark Nave was providing a good Force,
there was a dark Force propelling me out the door of my employer.  I owe as
much to a particularly unpleasant boss in this regard.

But I had had such in the past with no such response or even consideration
on my part, so it took both the bad Force of a bad boss and the good Force
to push me successfully in the right direction.

Ken Javor
Phone: (256) 650-5261



From: Douglas Smith 
Reply-To: Douglas Smith 
Date: Wed, 20 Jun 2018 09:16:45 -0700
To: 
Subject: Re: [PSES] ESD question


I also have a copy of those waveforms and a paper Michael King wrote on one
of my older Macs, can likely find it if needed.

I was lucky to have been mentored by Michael King when I was younger. He is
a great scientist/engineer and had a great effect on me.

I was fortunate to have four great mentors in my life: my Father, George
Florio (who got me into this field at age ten and helped me to become an
engineer by age 14), Henry Ott, and Michael King. I can¹t imagine my life
without these great men.

Maybe others can post about mentors who helped them become engineers.

Doug Smith
Sent from my iPhone
IPhone:  408-858-4528
Office:702-570-6108
Email: d...@dsmith.org
Website: http://dsmith.org

On Wed, Jun 20, 2018 at 8:52, John Woodgate  wrote:
> 
>  
> 
> It's probably not ethnicity directly, but skin resistance. This varies greatly
> between people. Long years ago, when we had touch-contact channel change on
> TVs, we had to double the sensitivity so that one particular person in the lab
> could work it. When we took sets to a show, someone turned up who couldn't
> work it.  We found it necessary to double the sensitivity again.  If you think
> about a person standing in the ESD field as a large (poorly-) conducting body,
> you can see why the effect can occur.
>  
>  
> John Woodgate OOO-Own Opinions Only
> J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
> Rayleigh, Essex UK
>  
> On 2018-06-20 14:06, Jim Hulbert wrote:
>  
>  
>>  
>>  
>> 
>> Somewhere, I have copies of the discharge waveforms (captured on a scope)
>> from human subjects that Michael King recruited during his studies.  As I
>> recall, the amplitude of the ESD pulses was limited to about 10kV as the
>> subjects started to balk.
>>  
>>  
>>  
>> I believe Michael¹s studies also led to the development of the Andy Hish 255
>> probe.  The waveform from that probe, which was a long wand grasped in the
>> hand, was influenced by the human body capacitance of the technician
>> performing the tests.   There was a situation some years ago in our EMC Lab,
>> where my associate and I both consistently passed a product for ESD using the
>> Andy Hish probe, which was our corporate standard tester at the time.
>> However, an intern working with us consistently failed the product.  We did
>> our best to make sure we were all following the exact same test technique.
>> The only difference my associate and I could think of was that the intern was
>> of a different ethnicity than us.  We didn¹t dare mention that, however.
>>  
>>  
>>  
>>  
>> 
>> Jim Hulbert
>>  
>>  
>>  
>>  
>>  
>>  
>  
>  
> -
> 
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> 
> 
> All emc-pstc postings are archived and searchable on the web at:
> h

Re: [PSES] ESD question

[Douglas Smith]

I also have a copy of those waveforms and a paper Michael King wrote on one of 
my older Macs, can likely find it if needed.
I was lucky to have been mentored by Michael King when I was younger. He is a 
great scientist/engineer and had a great effect on me.

I was fortunate to have four great mentors in my life: my Father, George Florio 
(who got me into this field at age ten and helped me to become an engineer by 
age 14), Henry Ott, and Michael King . I can’t imagine my life without these 
great men.
Maybe others can post about mentors who helped them become engineers.
Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: 
d...@dsmith.org Website: http://dsmith.org
On Wed, Jun 20, 2018 at 8:52, John Woodgate  wrote:
It's probably not ethnicity directly, but skin resistance. This varies greatly 
between people. Long years ago, when we had touch-contact channel change on 
TVs, we had to doubl e the sensitiv ity so that one particular person in the 
lab could work it. When we took sets to a show, someone tur ned up who couldn't 
work it. We found it necessary to double the sensitivity again. If you think 
about a person standing in the ESD field as a large (poorly-) conducting body, 
you can see why the effect can occur.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk [http://www.woodjohn.uk]
Rayleigh, Essex UK

On 2018-06-20 14:06, Jim Hulbert wrote:
Somewhere, I have copies of the discharge waveforms (captured on a scope) from 
human subjects that Michael King recruited during his studies. As I recall, the 
amplitude of the ESD pulses was limited to about 10kV as the subjects started 
to balk.



I believe Michael’s studies also led to the development of the Andy Hish 255 
probe. The waveform from that probe, which was a long wand grasped in the hand, 
was influenced by the human body capacitance of the technician performing the 
tests. There was a situation some years ago in our EMC Lab, where my associate 
and I both consistently passed a product for ESD using the Andy Hish probe, 
which was our corporate standard tester at the time. However, an intern working 
with us consistently failed the product. We did our best to make sure we were 
all following the exact same test technique. The only difference my associate 
and I could think of was that the intern was of a different ethnicity than us. 
We didn’t dare mention that, however.



Jim Hulbert





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Re: [PSES] ESD question

[John Woodgate]

It's probably not ethnicity directly, but skin resistance. This varies 
greatly between people. Long years ago, when we had touch-contact 
channel change on TVs, we had to double the sensitivity so that one 
particular person in the lab could work it. When we took sets to a show, 
someone turned up who couldn't work it.  We found it necessary to double 
the sensitivity again.  If you think about a person standing in the ESD 
field asa large (poorly-) conducting body, you can see why the effect 
can occur.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-06-20 14:06, Jim Hulbert wrote:


Somewhere, I have copies of the discharge waveforms (captured on a 
scope) from human subjects that Michael King recruited during his 
studies.  As I recall, the amplitude of the ESD pulses was limited to 
about 10kV as the subjects started to balk.


I believe Michael’s studies also led to the development of the Andy 
Hish 255 probe.  The waveform from that probe, which was a long wand 
grasped in the hand, was influenced by the human body capacitance of 
the technician performing the tests.   There was a situation some 
years ago in our EMC Lab, where my associate and I both consistently 
passed a product for ESD using the Andy Hish probe, which was our 
corporate standard tester at the time.  However, an intern working 
with us consistently failed the product.  We did our best to make sure 
we were all following the exact same test technique.   The only 
difference my associate and I could think of was that the intern was 
of a different ethnicity than us.  We didn’t dare mention that, however.


*Jim Hulbert*





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Re: [PSES] ESD question

[John Woodgate]

Hello, Doug. As you know, the 'spherical model' is a classic joke about 
physicists, but only half-joking because they do workas long as you 
don't 'push' the model too far.  Take a human of 80 kg who just floats, 
they seem to have a 'spherical' capacitance of 300 pF (but  I don't 
trust my arithmetic this early in the morning).


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-06-20 00:10, Doug Smith wrote:

Hi John and the group,

Actually I was just kidding everyone. But I am going to start telling 
everyone my body is about 24 pF/ns and see what happens. I will keep 
an eye open for the men in the white coats with nets. Actually I have 
been watching for them for some time now. Just completed a run at 100 
F. Will be running in 111+ F on Thursday at the peak of the afternoon. 
Some day I will act my age.


Doug



On Tue, 19 Jun 2018 22:29:44 +0100, John Woodgate wrote:

I think the model should assume a spherical body of the relevant mass, 
which capacitance in the archaic unit 'centimetres' is equal to its 
radius in cm,  and 1 cm = 1.13 pF. With all respect to Doug, I think 
the BCI is about as scientific as BMI, which is at least a pressure 
(kg/metre-squared) of some sort. I'm not sure what pF/ns would represent.


Of course the capacitance of a spherical grandmother of any radius is 
1 nanafarad.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associateswww.woodjohn.uk
Rayleigh, Essex UK
On 2018-06-19 22:06, Doug Smith wrote:

Hi Ken and the group,

The model started out in IEC 801-2 which had a 150 Ohm, 150 pF model. 
This eventually became IEC 6000-4-2 at 330 Ohms and 150 pF. Both were 
meant to model a piece of metal in a human hand. Such a discharge is 
an order of magnitude more severe, even for a tiny piece of metal in 
one's hand, than a discharge directly from a human hand if one 
measures the radiated EMI from these events.


The R and C above were the result of many measurements on people. The 
first engineers to describe the IEC 61000-4-2 pulse as it is today, 
with the sharp peak at the start, was Michael King and David Reynolds 
back when dinosaurs roamed the earth in the last century.


There is a semiconductor device handling spec called "Human Body 
Model" using 100 pF and 1500 Ohms. But, for me, there are no good HBM 
simulators on the market as they all have metallic tips. They need a 
tip composed of material that has the same volume and surface 
resistivity as a human finger. There it goes, now no one can patent 
the idea...it is now in the public domain.


Since capacitance goes by surface area, we may need a new capacitance 
value as the population has gained weight. I propose we replace BMI 
(Body Mass Index) with the BCI (Body Capacitance Index) a combination 
of body free space capacitance in pF of a person and the number of 
nanoseconds (at one foot per nanosecond) it takes for light to go from 
head to foot. Like BCI = [body capacitance]/[body length in 
nanoseconds at the speed of light]. For me that might be about 25 
pF/ns. Some of my friends might be about 45 pF/ns.


Wow, two ideas in the same email!

Doug


On Tue, 19 Jun 2018 15:34:57 -0500, Ken Javor wrote:


What with Doug Smith being active in this sort of standard writing 
activity, I doubt it’s simply inertia.


Ken Javor
Phone: (256) 650-5261



*From: *John Woodgate 
*Date: *Tue, 19 Jun 2018 21:26:38 +0100
*To: *Ken Javor , 


*Subject: *Re: [PSES] ESD question



Probably handed down on a stone tablet in 1910 and no-one had the 
courage to challenge it yet. (;-)



John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> 
<http://www.woodjohn.uk>

Rayleigh, Essex UK

On 2018-06-19 21:18, Ken Javor wrote:

ESD question Anyone out there know the origins of the 150 pF/330
ohm gun model used in EN61000-4-2 and derivative standards? It
seems it ought to be a human body model, but it isn't.

 Ken Javor
 Phone: (256) 650-5261 -
 


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Re: [PSES] ESD question

[Doug Smith]

Hi John and the group,

Actually I was just kidding everyone. But I am going to start telling everyone 
my body is about 24 pF/ns and see what happens. I will keep an eye open for the 
men in the white coats with nets. Actually I have been watching for them for 
some time now. Just completed a run at 100 F. Will be running in 111+ F on 
Thursday at the peak of the afternoon. Some day I will act my age.

Doug








On Tue, 19 Jun 2018 22:29:44 +0100, John Woodgate  wrote:


I think the model should assume a spherical body of the relevant mass, which 
capacitance in the archaic unit 'centimetres' is equal to its radius in 
cm, and 1 cm = 1.13 pF. With all respect to Doug, I think the BCI is 
about as scientific as BMI, which is at least a pressure (kg/metre-squared) of 
some sort. I'm not sure what pF/ns would represent. 

Of course the capacitance of a spherical grandmother of any radius is 1 
nanafarad.

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-06-19 22:06, Doug Smith wrote:







Hi Ken and the group,

The model started out in IEC 801-2 which had a 150 Ohm, 150 pF model. This 
eventually became IEC 6000-4-2 at 330 Ohms and 150 pF. Both were meant to model 
a piece of metal in a human hand. Such a discharge is an order of magnitude 
more severe, even for a tiny piece of metal in one's hand, than a discharge 
directly from a human hand if one measures the radiated EMI from these events.

The R and C above were the result of many measurements on people. The first 
engineers to describe the IEC 61000-4-2 pulse as it is today, with the sharp 
peak at the start, was Michael King and David Reynolds back when dinosaurs 
roamed the earth in the last century.

There is a semiconductor device handling spec called "Human Body Model" using 
100 pF and 1500 Ohms. But, for me, there are no good HBM simulators on the 
market as they all have metallic tips. They need a tip composed of material 
that has the same volume and surface resistivity as a human finger. There it 
goes, now no one can patent the idea...it is now in the public domain.

Since capacitance goes by surface area, we may need a new capacitance value as 
the population has gained weight. I propose we replace BMI (Body Mass Index) 
with the BCI (Body Capacitance Index) a combination of body free space 
capacitance in pF of a person and the number of nanoseconds (at one foot per 
nanosecond) it takes for light to go from head to foot. Like BCI = [body 
capacitance]/[body length in nanoseconds at the speed of light]. For me that 
might be about 25 pF/ns. Some of my friends might be about 45 pF/ns.

Wow, two ideas in the same email!

Doug



On Tue, 19 Jun 2018 15:34:57 -0500, Ken Javor  wrote:



What with Doug Smith being active in this sort of standard writing activity, I 
doubt it’s simply inertia.

Ken Javor
Phone: (256) 650-5261



From: John Woodgate j...@woodjohn.uk
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor ken.ja...@emccompliance.com, 
EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question



Probably handed down on a stone tablet in 1910 and no-one had the courage to 
challenge it yet. (;-)


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk http://www.woodjohn.uk;
Rayleigh, Essex UK

On 2018-06-19 21:18, Ken Javor wrote:



ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model 
used in EN61000-4-2 and derivative standards? It seems it ought to be a human 
body model, but it isn't.

Ken Javor
Phone: (256) 650-5261 -



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Re: [PSES] ESD question

[Doug Smith]

Hi Chas,

I think at the time Michael King was developing the data for modern standards 
on ESD, David Pommerenke was likely just starting kindergarten. David came 
around much later, even later than the extensive work at Bell Labs I 
participated in characterizing simulators of the time. The model of the 
simulator predates David's work by many years as far as I know.

Doug








On Tue, 19 Jun 2018 21:08:16 +, "Grasso, Charles"  wrote:

  








Ken,



The gun model is derived from extensive research by Mike King and others (David 
Pommerenke) to derive
a pulse that reflects an ESD event from a human with an intervening metal 
object. 



I have copied Mike for his input. Dr Pommerenke is on the EMC blog.





Thanks



Charles Grasso

(w) 303-706-5467











From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Tuesday, June 19, 2018 2:35 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question





This message originated outside of DISH and was sent by: 
owner-emc-p...@listserv.ieee.org 

What with Doug Smith being active in this sort of standard writing activity, I 
doubt it’s simply inertia.

Ken Javor
Phone: (256) 650-5261







From: John Woodgate j...@woodjohn.uk
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor ken.ja...@emccompliance.com, 
EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question



Probably handed down on a stone tablet in 1910 and no-one had the courage to 
challenge it yet. (;-)


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk  http://www.woodjohn.uk;
Rayleigh, Essex UK

On 2018-06-19 21:18, Ken Javor wrote:




ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model 
used in EN61000-4-2 and derivative standards? It seems it ought to be a human 
body model, but it isn't.

Ken Javor
Phone: (256) 650-5261 -



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discussion list. To post a message to the list, send your e-mail to 
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Re: [PSES] ESD question

[Ken Javor]

This is going downhill fast but I¹m enjoying the ride!

Ken Javor
Phone: (256) 650-5261




From: John Woodgate 
Reply-To: John Woodgate 
Date: Tue, 19 Jun 2018 22:29:44 +0100
To: 
Subject: Re: [PSES] ESD question

   

I think the model should assume a spherical body of the relevant mass, which
capacitance in the archaic unit 'centimetres' is equal to its radius in cm, 
and 1 cm = 1.13 pF. With all respect to Doug, I think the BCI is about as
scientific as BMI, which is at least a pressure (kg/metre-squared) of some
sort. I'm not sure what pF/ns would represent. 
 
 

Of course the capacitance of a spherical grandmother of any radius is 1
nanafarad.
 
 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
Rayleigh, Essex UK
 
On 2018-06-19 22:06, Doug Smith wrote:
 
 
>   
> Hi Ken and the group,
>  
>  The model started out in IEC 801-2 which had a 150 Ohm, 150 pF model. This
> eventually became IEC 6000-4-2 at 330 Ohms and 150 pF. Both were meant to
> model a piece of metal in a human hand. Such a discharge is an order of
> magnitude more severe, even for a tiny piece of metal in one's hand, than a
> discharge directly from a human hand if one measures the radiated EMI from
> these events.
>  
>  The R and C above were the result of many measurements on people. The first
> engineers to describe the IEC 61000-4-2 pulse as it is today, with the sharp
> peak at the start, was Michael King and David Reynolds back when dinosaurs
> roamed the earth in the last century.
>  
>  There is a semiconductor device handling spec called "Human Body Model" using
> 100 pF and 1500 Ohms. But, for me, there are no good HBM simulators on the
> market as they all have metallic tips. They need a tip composed of material
> that has the same volume and surface resistivity as a human finger. There it
> goes, now no one can patent the idea...it is now in the public domain.
>  
>  Since capacitance goes by surface area, we may need a new capacitance value
> as the population has gained weight. I propose we replace BMI (Body Mass
> Index) with the BCI (Body Capacitance Index) a combination of body free space
> capacitance in pF of a person and the number of nanoseconds (at one foot per
> nanosecond) it takes for light to go from head to foot. Like BCI = [body
> capacitance]/[body length in nanoseconds at the speed of light]. For me that
> might be about 25 pF/ns. Some of my friends might be about 45 pF/ns.
>  
>  Wow, two ideas in the same email!
>  
>  Doug   
> 
>
>  
>  On Tue, 19 Jun 2018 15:34:57 -0500, Ken Javor  wrote:
>  
>  
>   What with Doug Smith being active in this sort of standard writing activity,
> I doubt it¹s simply inertia.
>  
>  Ken Javor
>  Phone: (256) 650-5261
>  
>  
>    
> 
> From: John Woodgate  <mailto:j...@woodjohn.uk>
>  Date: Tue, 19 Jun 2018 21:26:38 +0100
>  To: Ken Javor 
> <mailto:ken.ja...@emccompliance.com> , 
> <mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
>  Subject: Re: [PSES] ESD question
>  
>     
>  
>  Probably handed down on a stone tablet in 1910 and no-one had the courage to
> challenge it yet. (;-)
>  
>   
>  John Woodgate OOO-Own Opinions Only
>  J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
> <http://www.woodjohn.uk>
>  Rayleigh, Essex UK
>   
>  On 2018-06-19 21:18, Ken Javor wrote:
>   
>    
>> ESD question Anyone out there know the origins of the 150 pF/330 ohm gun
>> model used in EN61000-4-2 and derivative standards? It seems it ought to be a
>> human body model, but it isn't.
>>   
>>   Ken Javor
>>   Phone: (256) 650-5261 -
>>  
>>   
>>  
>>  This message is from the IEEE Product Safety Engineering Society emc-pstc
>> discussion list. To post a message to the list, send your e-mail to
>>  <mailto:emc-p...@ieee.org>
>>   
>>  
>>  All emc-pstc postings are archived and searchable on the web at:
>> http://www.ieee-pses.org/emc-pstc.html
>>   
>>  
>>  Attachments are not permitted but the IEEE PSES Online Communities site at
>> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
>> formats), large files, etc.
>>   
>>  
>>  Website: http://www.ieee-pses.org/
>>   Instructions: http://www.ieee-pses.org/list.html (including how to
>> unsubscribe) <http://www.ieee-pses.org/list.html>
>>   List rules: http://www.ieee-pses.org/listrules.html
>>   
>>  
>>  For help, send mail to the list administrators:
>>   Scott Douglas  <mailto:sdoug...@ieee.org>
>>   Mike 

Re: [PSES] ESD question

[Grasso, Charles]

Ken,

The gun model is derived from extensive research by Mike King and others (David 
Pommerenke) to derive
a pulse that reflects an ESD event from a human with an intervening metal 
object.

I have copied Mike for his input. Dr Pommerenke is on the EMC blog.


Thanks

Charles Grasso
(w) 303-706-5467




From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Tuesday, June 19, 2018 2:35 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question


 This message originated outside of DISH and was sent by: 
owner-emc-p...@listserv.ieee.org<mailto:owner-emc-p...@listserv.ieee.org>
What with Doug Smith being active in this sort of standard writing activity, I 
doubt it's simply inertia.

Ken Javor
Phone: (256) 650-5261



From: John Woodgate mailto:j...@woodjohn.uk>>
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor 
mailto:ken.ja...@emccompliance.com>>, 
mailto:EMC-PSTC@LISTSERV.IEEE.ORG>>
Subject: Re: [PSES] ESD question



Probably handed down on a stone tablet in 1910 and no-one had the courage to 
challenge it yet. (;-)


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk<http://www.woodjohn.uk> 
<http://www.woodjohn.uk><http://www.woodjohn.uk>
Rayleigh, Essex UK

On 2018-06-19 21:18, Ken Javor wrote:


ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model 
used in EN61000-4-2 and derivative standards? It seems it ought to be a human 
body model, but it isn't.

 Ken Javor
 Phone: (256) 650-5261 -
 


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
mailto:emc-p...@ieee.org>>


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 Instructions: http://www.ieee-pses.org/list.html (including how to 
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 List rules: http://www.ieee-pses.org/listrules.html


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 Scott Douglas mailto:sdoug...@ieee.org>>
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 Jim Bacher mailto:j.bac...@ieee.org>>
 David Heald mailto:dhe...@gmail.com>>



-


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Re: [PSES] ESD question

[Ken Javor]

My purpose was solely to research the rationale (which I should have found
on my own in my 1995 copy, but didn¹t until the 2008 wording was presented).
For my immediate purpose, the official rationale suffices.

Ken Javor
Phone: (256) 650-5261



From: John Woodgate 
Reply-To: John Woodgate 
Date: Tue, 19 Jun 2018 22:14:46 +0100
To: 
Subject: Re: [PSES] ESD question

   

Yes, that's what Annex A says, but it's still a stone tablet. 'determined',
'shown'; by whom? when?  I'm not attacking the committee, because it may
well be impossible to do better. But we should understand what sort of
information or data we are using. I have been known to liken most of EMC
testing to 'measuring jelly (Jello) with a micrometer'.
 
 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
Rayleigh, Essex UK
 
On 2018-06-19 22:05, Ken Javor wrote:
 
 
>  Re: [PSES] ESD question Thank you!
>  
>  Ken Javor
>  Phone: (256) 650-5261
>  
>  
>  
>  
> 
> From: "Schaefer, David" 
> <mailto:david.schae...@tuvsud.com>
>  Date: Tue, 19 Jun 2018 20:56:57 +
>  To: Ken Javor 
> <mailto:ken.ja...@emccompliance.com> , "EMC-PSTC@LISTSERV.IEEE.ORG"
> <mailto:EMC-PSTC@LISTSERV.IEEE.ORG>  
> <mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
>  Conversation: [PSES] ESD question
>  Subject: RE: [PSES] ESD question
>  
>  Ken, 
>   
>  Annex A in the 2008 edition has this to say:
>   
>  A.7 Selection of elements for the ESD generator
>  A storage capacitance shall be used which is representative of the
> capacitance of the human
>  body. A typical value of 150 pF has been determined suitable for this
> purpose.
>  A resistance of 330 Ohms has been chosen to represent the source resistance
> of a human body
>  holding a metallic object such as a key or tool. It has been shown that this
> metal discharge
>  situation is sufficiently severe to represent all human discharges in the
> field.
>    
>  
 
 -


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Re: [PSES] ESD question

[Ken Javor]

What I glean from the below that wasn¹t in the other responses is that while
the measurements on human body capacity were made some time ago (when
dinosaurs roamed the earth), it might in fact be worthwhile to reexamine the
measurements, because the dinosaurs have evolved and grown larger...

:-)

Ken Javor
Phone: (256) 650-5261



From: Doug Smith 
Reply-To: 
Date: Tue, 19 Jun 2018 17:06:06 -0400
To: , 
Subject: Re: [PSES] ESD question

Hi Ken and the group,

The model started out in IEC 801-2 which had a 150 Ohm, 150 pF model. This
eventually became IEC 6000-4-2 at 330 Ohms and 150 pF. Both were meant to
model a piece of metal in a human hand. Such a discharge is an order of
magnitude more severe, even for a tiny piece of metal in one's hand, than a
discharge directly from a human hand if one measures the radiated EMI from
these events.

The R and C above were the result of many measurements on people. The first
engineers to describe the IEC 61000-4-2 pulse as it is today, with the sharp
peak at the start, was Michael King and David Reynolds back when dinosaurs
roamed the earth in the last century.

There is a semiconductor device handling spec called "Human Body Model"
using 100 pF and 1500 Ohms. But, for me, there are no good HBM simulators on
the market as they all have metallic tips. They need a tip composed of
material that has the same volume and surface resistivity as a human finger.
There it goes, now no one can patent the idea...it is now in the public
domain.

Since capacitance goes by surface area, we may need a new capacitance value
as the population has gained weight. I propose we replace BMI (Body Mass
Index) with the BCI (Body Capacitance Index) a combination of body free
space capacitance in pF of a person and the number of nanoseconds (at one
foot per nanosecond) it takes for light to go from head to foot. Like BCI =
[body capacitance]/[body length in nanoseconds at the speed of light]. For
me that might be about 25 pF/ns. Some of my friends might be about 45 pF/ns.

Wow, two ideas in the same email!

Doug 



On Tue, 19 Jun 2018 15:34:57 -0500, Ken Javor  wrote:


What with Doug Smith being active in this sort of standard writing activity,
I doubt it¹s simply inertia.

Ken Javor
Phone: (256) 650-5261


 

From: John Woodgate 
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor , 
Subject: Re: [PSES] ESD question

   

Probably handed down on a stone tablet in 1910 and no-one had the courage to
challenge it yet. (;-)

 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
Rayleigh, Essex UK
 
On 2018-06-19 21:18, Ken Javor wrote:
 
 
> ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model
> used in EN61000-4-2 and derivative standards? It seems it ought to be a human
> body model, but it isn't.
>  
>  Ken Javor
>  Phone: (256) 650-5261 -
>  
>  
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> 
>  
> 
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>  
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
> formats), large files, etc.
>  
> 
> Website: http://www.ieee-pses.org/
>  Instructions: http://www.ieee-pses.org/list.html (including how to
> unsubscribe) <http://www.ieee-pses.org/list.html>
>  List rules: http://www.ieee-pses.org/listrules.html
>  
> 
> For help, send mail to the list administrators:
>  Scott Douglas 
>  Mike Cantwell 
>  
> 
> For policy questions, send mail to:
>  Jim Bacher 
>  David Heald 
>  

 
-


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Re: [PSES] ESD question

[John Woodgate]

Yes, that's what Annex A says, but it's still a stone tablet. 
'determined', 'shown'; by whom? when?  I'm not attacking the committee, 
because it may well be impossible to do better. But we should understand 
what sort of information or data we are using. I have been known to 
liken most of EMC testing to 'measuring jelly (Jello) with a micrometer'.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-06-19 22:05, Ken Javor wrote:

Re: [PSES] ESD question Thank you!

Ken Javor
Phone: (256) 650-5261




*From: *"Schaefer, David" 
*Date: *Tue, 19 Jun 2018 20:56:57 +
*To: *Ken Javor , 
"EMC-PSTC@LISTSERV.IEEE.ORG" 

*Conversation: *[PSES] ESD question
*Subject: *RE: [PSES] ESD question

Ken,

Annex A in the 2008 edition has this to say:

*A.7 Selection of elements for the ESD generator
*A storage capacitance shall be used which is representative of the 
capacitance of the human
body. A typical value of 150 pF has been determined suitable for this 
purpose.
A resistance of 330 Ohms has been chosen to represent the source 
resistance of a human body
holding a metallic object such as a key or tool. It has been shown 
that this metal discharge
situation is sufficiently severe to represent all human discharges in 
the field.





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Re: [PSES] ESD question

[Ken Javor]

Thank you!

Ken Javor
Phone: (256) 650-5261




From: "Schaefer, David" 
Date: Tue, 19 Jun 2018 20:56:57 +
To: Ken Javor , "EMC-PSTC@LISTSERV.IEEE.ORG"

Conversation: [PSES] ESD question
Subject: RE: [PSES] ESD question

Ken, 
 
Annex A in the 2008 edition has this to say:
 
A.7 Selection of elements for the ESD generator
A storage capacitance shall be used which is representative of the
capacitance of the human
body. A typical value of 150 pF has been determined suitable for this
purpose.
A resistance of 330 Ohms has been chosen to represent the source resistance
of a human body
holding a metallic object such as a key or tool. It has been shown that this
metal discharge
situation is sufficiently severe to represent all human discharges in the
field.
 
 
Thanks,
 
David
 
 

From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Tuesday, June 19, 2018 3:35 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question
 
What with Doug Smith being active in this sort of standard writing activity,
I doubt it¹s simply inertia.

Ken Javor
Phone: (256) 650-5261



From: John Woodgate 
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor , 
Subject: Re: [PSES] ESD question

   

Probably handed down on a stone tablet in 1910 and no-one had the courage to
challenge it yet. (;-)

 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
<http://www.woodjohn.uk>
Rayleigh, Essex UK
 
On 2018-06-19 21:18, Ken Javor wrote:
 
 
> ESD question Anyone out there know the origins of the 150 pF/330 ohm gun model
> used in EN61000-4-2 and derivative standards? It seems it ought to be a human
> body model, but it isn't.
>  
>  Ken Javor
>  Phone: (256) 650-5261 -
>  
>  
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> 
>  
> 
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>  
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
> formats), large files, etc.
>  
> 
> Website: http://www.ieee-pses.org/
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> unsubscribe) <http://www.ieee-pses.org/list.html>
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>  
> 
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Re: [PSES] ESD question

[John Woodgate]

The inertia in the committee that studies ESD is very large indeed. 
No-one wants to have to throw away all their test gear and buy new, and 
no-one wants to re-test and debug running products. As long as the 
current standard keeps field returns for ESD damage to an acceptable 
minimum, it won't be changed.


The question, 'Cui bono?' ought to be asked a lot in EMC committees.

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-06-19 21:34, Ken Javor wrote:
Re: [PSES] ESD question What with Doug Smith being active in this sort 
of standard writing activity, I doubt it’s simply inertia.


Ken Javor
Phone: (256) 650-5261




*From: *John Woodgate 
*Date: *Tue, 19 Jun 2018 21:26:38 +0100
*To: *Ken Javor , 


*Subject: *Re: [PSES] ESD question



Probably handed down on a stone tablet in 1910 and no-one had the 
courage to challenge it yet. (;-)



John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> 
<http://www.woodjohn.uk>

Rayleigh, Essex UK

On 2018-06-19 21:18, Ken Javor wrote:


ESD question Anyone out there know the origins of the 150 pF/330
ohm gun model used in EN61000-4-2 and derivative standards? It
seems it ought to be a human body model, but it isn't.

 Ken Javor
 Phone: (256) 650-5261 -
 


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Re: [PSES] ESD question

[Ken Javor]

What with Doug Smith being active in this sort of standard writing activity,
I doubt it¹s simply inertia.

Ken Javor
Phone: (256) 650-5261




From: John Woodgate 
Date: Tue, 19 Jun 2018 21:26:38 +0100
To: Ken Javor , 
Subject: Re: [PSES] ESD question

   

Probably handed down on a stone tablet in 1910 and no-one had the courage to
challenge it yet. (;-)
 
 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
Rayleigh, Essex UK
 
On 2018-06-19 21:18, Ken Javor wrote:
 
 
>  ESD question Anyone out there know the origins of the 150 pF/330 ohm gun
> model used in EN61000-4-2 and derivative standards? It seems it ought to be a
> human body model, but it isn't.
>  
>  Ken Javor
>  Phone: (256) 650-5261 -
>  
>  
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> 
>  
> 
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>  
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at
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> formats), large files, etc.
>  
> 
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> unsubscribe) <http://www.ieee-pses.org/list.html>
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Re: [PSES] ESD question

[John Woodgate]

Probably handed down on a stone tablet in 1910 and no-one had the 
courage to challenge it yet. (;-)


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-06-19 21:18, Ken Javor wrote:
ESD question Anyone out there know the origins of the 150 pF/330 ohm 
gun model used in EN61000-4-2 and derivative standards? It seems it 
ought to be a human body model, but it isn't.


Ken Javor
Phone: (256) 650-5261 -


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[PSES] ESD question

[Ken Javor]

Anyone out there know the origins of the 150 pF/330 ohm gun model used in
EN61000-4-2 and derivative standards? It seems it ought to be a human body
model, but it isn't.

Ken Javor
Phone: (256) 650-5261

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Re: [PSES] ESD question

[Doug Smith]

True, but for breaking down system barriers 50 nH is very small compared to 
things like a wire grounding a metal piece in the system or the power cord 
itself.

I have seen EMI filters on power supplies cause the supply to breakdown in 
response to 800 V ESD (power supply either unpowered or powered) and do it a 
half dozen times for one ESD hit. Not quite the same thing but it shows how 
insidious ESD can be.

Doug








On Sun, 7 Jan 2018 18:02:39 -0600, Ken Javor  wrote:






Agreed using numbers below, but 50 nH is huge compared to the loop area on a 
typical PCB that will see the coupling.

Ken Javor
Phone: (256) 650-5261



From: Douglas Smith d...@emcesd.com
Reply-To: Douglas Smith d...@emcesd.com
Date: Sun, 7 Jan 2018 10:19:40 -0800
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question


Actually, inductive coupling (Faraday's law) can generate thousand of Volts 
near ESD events, enough to breakdown insulation barriers!

Just get a di/dt of 40 Amps/ns (a 10kV or somewhat less contact discharge) near 
a loop and see what you get for 50 nH of inductance (not much)

E = 40A/ns * 50 nH = 2,000 Volts

Doug Smith
Sent from my iPhone
IPhone: 408-858-4528
Office: 702-570-6108
Email: d...@dsmith.org
Website: http://dsmith.org

On Sun, Jan 7, 2018 at 8:09, Cortland Richmond k...@earthlink.net wrote:

We are sometimes less than precise -- but it leads to interesting discussions.

Cheers,


Cortland Richmond

-Original Message-
From: Ken Javor
Sent: Jan 7, 2018 9:28 AM
To: Cortland Richmond , EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question

Re: [PSES] ESD question Cortland: Faraday Law purely inductive coupling from an 
ESD event doesn't cause potentials that breakdown dielectric barriers; it 
induces potentials that cause bit shifts. But to answer John Woodgate’s 
question literally, enough charge buildup with some capacitance eventually 
yields a potential high enough to cause dielectric breakdown. Since that is 
basic, I assume I misinterpreted his post.

Ken Javor
Phone: (256) 650-5261


From: Cortland Richmond k...@earthlink.net
Reply-To: Cortland Richmond k...@earthlink.net
Date: Sun, 7 Jan 2018 06:23:07 -0500
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question

Induction; I once saw motherboard testers shut down systems under test by just 
walking away from the work table at lunchtime. Sliding across the cloth chair 
seats generated a charge, and walking away biased the motherboards and shut 
everything down.

(They didn't have the funds for antistatic protection – so for a few months, we 
had them spraying the chairs with a solution of water and detergent. You could 
tell who worked there because the seats of their pants were wet...)


Cortland Richmond

-Original Message-
From: John Woodgate
Sent: Jan 7, 2018 4:10 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question



Philosophical issue there. If the field is really static, what changed to cause 
the spark to happen when it did, rather than at some other time? (A cosmic ray 
would breach the stasis.)


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk http://www.woodjohn.uk;
Rayleigh, Essex UK

On 2018-01-07 03:37, Doug Smith wrote:



Hi Ed and Ken,

An ESD event can be produced without any direct addition of charge. It only 
takes an E field and two conductors near each other as in:

http://emcesd.com/tt2001/tt060101.htm

http://emcesd.com/tt2001/tt050101.htm 
http://emcesd.com/tt2001/tt060101.htm;

Unobserved discharge not needed and generally is not involved with these type 
of events. Just a static E field will induce a spark.




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Re: [PSES] ESD question

[Ken Javor]

Agreed using numbers below, but 50 nH is huge compared to the loop area on a
typical PCB that will see the coupling.

Ken Javor
Phone: (256) 650-5261




From: Douglas Smith <d...@emcesd.com>
Reply-To: Douglas Smith <d...@emcesd.com>
Date: Sun, 7 Jan 2018 10:19:40 -0800
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] ESD question


 Actually, inductive coupling (Faraday's law) can generate thousand of Volts
near ESD events, enough to breakdown insulation barriers!

Just get a di/dt of 40 Amps/ns (a 10kV or somewhat less contact discharge)
near a loop and see what you get for 50 nH of inductance (not much)

E = 40A/ns * 50 nH = 2,000 Volts

Doug Smith
Sent from my iPhone
IPhone:  408-858-4528
Office:702-570-6108
Email: d...@dsmith.org
Website: http://dsmith.org

On Sun, Jan 7, 2018 at 8:09, Cortland Richmond <k...@earthlink.net> wrote:
> We are sometimes less than precise -- but it leads to interesting discussions.
> 
> Cheers,
> 
> 
> Cortland Richmond
> 
>> -Original Message-
>> From: Ken Javor 
>> Sent: Jan 7, 2018 9:28 AM
>> To: Cortland Richmond , EMC-PSTC@LISTSERV.IEEE.ORG
>> Subject: Re: [PSES] ESD question
>> 
>> Re: [PSES] ESD question Cortland: Faraday Law purely inductive coupling from
>> an ESD event doesn't cause potentials that breakdown dielectric barriers; it
>> induces potentials that cause bit shifts.  But to answer John Woodgate¹s
>> question literally, enough charge buildup with some capacitance eventually
>> yields a potential high enough to cause dielectric breakdown. Since that is
>> basic, I assume I misinterpreted his post.
>> 
>> Ken Javor
>> Phone: (256) 650-5261
>> 
>> 
>> 
>> From: Cortland Richmond <k...@earthlink.net>
>> Reply-To: Cortland Richmond <k...@earthlink.net>
>> Date: Sun, 7 Jan 2018 06:23:07 -0500
>> To: <EMC-PSTC@LISTSERV.IEEE.ORG>
>> Subject: Re: [PSES] ESD question
>> 
>> Induction; I once saw motherboard testers shut down systems under test by
>> just walking away from the work table at lunchtime.  Sliding across the cloth
>> chair seats generated a charge, and walking away biased the motherboards and
>> shut everything down.
>> 
>> (They didn't have the funds for antistatic protection ­ so for a few months,
>> we had them spraying the chairs with a solution of water and detergent. You
>> could tell who worked there because the seats of their pants were wet...)
>> 
>> 
>> Cortland Richmond
>>> -Original Message-
>>> From: John Woodgate
>>> Sent: Jan 7, 2018 4:10 AM
>>> To: EMC-PSTC@LISTSERV.IEEE.ORG
>>> Subject: Re: [PSES] ESD question
>>> 
>>>  
>>> 
>>> Philosophical issue there. If the field is really static, what changed to
>>> cause the spark to happen when it did, rather than at some other time? (A
>>> cosmic ray would breach the stasis.)
>>>  
>>>  
>>> John Woodgate OOO-Own Opinions Only
>>> J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
>>> Rayleigh, Essex UK
>>>  
>>> On 2018-01-07 03:37, Doug Smith wrote:
>>>  
>>>  
>>>>   
>>>> Hi Ed and Ken,
>>>>  
>>>>  An ESD event can be produced without any direct addition of charge. It
>>>> only takes an E field and two conductors near each other as in:
>>>>  
>>>>  http://emcesd.com/tt2001/tt060101.htm
>>>>  
>>>>  http://emcesd.com/tt2001/tt050101.htm
>>>> <http://emcesd.com/tt2001/tt060101.htm>
>>>>  
>>>>  Unobserved discharge not needed and generally is not involved with these
>>>> type of events. Just a static E field will induce a spark.
>>>>  
>>>>  
>>>>  
>>>  
>>>  -
>>> 
>>> 
>>> This message is from the IEEE Product Safety Engineering Society emc-pstc
>>> discussion list. To post a message to the list, send your e-mail to
>>> <emc-p...@ieee.org>
>>> 
>>> All emc-pstc postings are archived and searchable on the web at:
>>> http://www.ieee-pses.org/emc-pstc.html
>>> 
>>> Attachments are not permitted but the IEEE PSES Online Communities site at
>>> http://product-compliance.oc.ieee.org/ can be used for graphics (in
>>> well-used formats), large files, etc.
>>> 
>>> Website:  http://www.ieee-pses.org/
>>> Instructions:  http://www.ieee-pses.org/list.html (including how to

Re: [PSES] ESD question

[Douglas Smith]

Actually, inductive coupling (Faraday's law) can generate thousand of Volts 
near ESD events, enough to breakdown insulation barriers!
Just get a di/dt of 40 Amps/ns (a 10kV or somewhat less contact discharge) near 
a loop and see what you get for 50 nH of inductance (not much)
E = 40A/ns * 50 nH = 2,000 Volts

Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: 
d...@dsmith.org Website: http://dsmith.org
On Sun, Jan 7, 2018 at 8:09, Cortland Richmond <k...@earthlink.net> wrote:
We are sometimes less than precise -- but it leads to interesting discussions.

Cheers,


Cortland Richmond

-Original Message-
From: Ken Javor
Sent: Jan 7, 2018 9:28 AM
To: Cortland Richmond , EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question

Re: [PSES] ESD question Cortland: Faraday Law purely inductive coupling from an 
ESD event doesn't cause potentials that breakdown dielectric barriers; it 
induces potentials that cause bit shifts. But to answer John Woodgate’s 
question literally, enough charge buildup with some capacitance eventually 
yields a potential high enough to cause dielectric breakdown. Since that is 
basic, I assume I misinterpreted his post.

Ken Javor
Phone: (256) 650-5261





From: Cortland Richmond <k...@earthlink.net>
Reply-To: Cortland Richmond <k...@earthlink.net>
Date: Sun, 7 Jan 2018 06:23:07 -0500
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] ESD question

Induction; I once saw motherboard testers shut down systems under test by just 
walking away from the work table at lunchtime. Sliding across the cloth chair 
seats generated a charge, and walking away biased the motherboards and shut 
everything down.

(They didn't have the funds for antistatic protection – so for a few months, we 
had them spraying the chairs with a solution of water and detergent. You could 
tell who worked there because the seats of their pants were wet...)


Cortland Richmond
-Original Message-
From: John Woodgate
Sent: Jan 7, 2018 4:10 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question



Philosophical issue there. If the field is really static, what changed to cause 
the spark to happen when it did, rather than at some other time? (A cosmic ray 
would breach the stasis.)


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> 
[http://www.woodjohn.uk]
Rayleigh, Essex UK

On 2018-01-07 03:37, Doug Smith wrote:



Hi Ed and Ken,

An ESD event can be produced without any direct addition of charge. It only 
takes an E field and two conductors near each other as in:

http://emcesd.com/tt2001/tt060101.htm [http://emcesd.com/tt2001/tt060101.htm]

http://emcesd.com/tt2001/tt050101.htm [http://emcesd.com/tt2001/tt050101.htm] 
<http://emcesd.com/tt2001/tt060101.htm> [http://emcesd.com/tt2001/tt060101.htm]

Unobserved discharge not needed and generally is not involved with these type 
of events. Just a static E field will induce a spark.




-


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Re: [PSES] ESD question

[Cortland Richmond]

Title: Re: [PSES] ESD question
I was working at Tandy Computers, and the EMC department was often blamed for strange occurrences.  We perforce had to become experts at demonstrating causes not within our control, and the software compatibility lab with its bare motherboards was one case where I was able to use very basic physics to identify the separation of charges and pushing back before lunch  as locking the systems up.As far as I know, no one EVER commented on the wet bottoms staff in that room had to accept.  Other problems occurred from time to time and perhaps I should write them up for Banana Skins.Cortland Richmond-Original Message-
From: Ken Javor <ken.ja...@emccompliance.com>
Sent: Jan 7, 2018 10:50 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question






In Doug Smith’s demo of a spark gap and charged paper cup, there was movement of charge induced in the point closest the cup, and that generated a potential difference across the points.  So even though the total amount of charge may have been static, there was a change in local charge and hence potential difference across the points.

Since we are being philosophical here, it seems the same can be said of any ESD event, if the picture is big enough. That is, walking across a rug, petting a cat, or whatever activity “generates” the charge in fact doesn't generate any charge, it simply separates it and moves it around. Enough charge separation, we get a potential difference, electric field and eventual discharge.

So says Coulomb.

Ken Javor
Phone: (256) 650-5261


From: John Woodgate <j...@woodjohn.uk>
Reply-To: John Woodgate <j...@woodjohn.uk>
Date: Sun, 7 Jan 2018 15:00:00 +
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] ESD question

   

 If the charge is still building up, the field is not static in the region close to whatever the charge is building up on. Just a philosophical point.
 
 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk  
Rayleigh, Essex UK
 
On 2018-01-07 14:28, Ken Javor wrote:
 
 
 Re: [PSES] ESD question Cortland: Faraday Law purely inductive coupling from an ESD event doesn't cause potentials that breakdown dielectric barriers; it induces potentials that cause bit shifts.  But to answer John Woodgate’s question literally, enough charge buildup with some capacitance eventually yields a potential high enough to cause dielectric breakdown. Since that is basic, I assume I misinterpreted his post.
 
 Ken Javor
 Phone: (256) 650-5261
 
 
 
From: Cortland Richmond <k...@earthlink.net> <mailto:k...@earthlink.net> 
 Reply-To: Cortland Richmond <k...@earthlink.net> <mailto:k...@earthlink.net> 
 Date: Sun, 7 Jan 2018 06:23:07 -0500
 To: <EMC-PSTC@LISTSERV.IEEE.ORG> <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> 
 Subject: Re: [PSES] ESD question
 
 Induction; I once saw motherboard testers shut down systems under test by just walking away from the work table at lunchtime.  Sliding across the cloth chair seats generated a charge, and walking away biased the motherboards and shut everything down.
 
 (They didn't have the funds for antistatic protection – so for a few months, we had them spraying the chairs with a solution of water and detergent. You could tell who worked there because the seats of their pants were wet...)
 
 
 Cortland Richmond
  
-Original Message- 
 From: John Woodgate 
 Sent: Jan 7, 2018 4:10 AM 
 To: EMC-PSTC@LISTSERV.IEEE.ORG 
 Subject: Re: [PSES] ESD question 
 
  
 
 Philosophical issue there. If the field is really static, what changed to cause the spark to happen when it did, rather than at some other time? (A cosmic ray would breach the stasis.)
  
  
 John Woodgate OOO-Own Opinions Only
 J M Woodgate and Associates www.woodjohn.uk    
 Rayleigh, Essex UK
  
 On 2018-01-07 03:37, Doug Smith wrote:
  
  
  
  
 Hi Ed and Ken,
  
  An ESD event can be produced without any direct addition of charge. It only takes an E field and two conductors near each other as in:
  
  http://emcesd.com/tt2001/tt060101.htm
  
  http://emcesd.com/tt2001/tt050101.htm  
  
  Unobserved discharge not needed and generally is not involved with these type of events. Just a static E field will induce a spark.
  
  
  
 
  
  -

 
 This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> <mailto:emc-p...@ieee.org> 
 
 All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html
 
 Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc.
 
 Website:  http://www.ieee-pses.org/
 Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)

Re: [PSES] ESD question

[Cortland Richmond]

Title: Re: [PSES] ESD question
We are sometimes less than precise -- but it leads to interesting discussions.Cheers,Cortland Richmond-Original Message-
From: Ken Javor <ken.ja...@emccompliance.com>
Sent: Jan 7, 2018 9:28 AM
To: Cortland Richmond <k...@earthlink.net>, EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question






Cortland: Faraday Law purely inductive coupling from an ESD event doesn't cause potentials that breakdown dielectric barriers; it induces potentials that cause bit shifts.  But to answer John Woodgate’s question literally, enough charge buildup with some capacitance eventually yields a potential high enough to cause dielectric breakdown. Since that is basic, I assume I misinterpreted his post.

Ken Javor
Phone: (256) 650-5261


From: Cortland Richmond <k...@earthlink.net>
Reply-To: Cortland Richmond <k...@earthlink.net>
Date: Sun, 7 Jan 2018 06:23:07 -0500
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] ESD question

Induction; I once saw motherboard testers shut down systems under test by just walking away from the work table at lunchtime.  Sliding across the cloth chair seats generated a charge, and walking away biased the motherboards and shut everything down.

(They didn't have the funds for antistatic protection – so for a few months, we had them spraying the chairs with a solution of water and detergent. You could tell who worked there because the seats of their pants were wet...)


Cortland Richmond
-Original Message- 
From: John Woodgate 
Sent: Jan 7, 2018 4:10 AM 
To: EMC-PSTC@LISTSERV.IEEE.ORG 
Subject: Re: [PSES] ESD question 

 

Philosophical issue there. If the field is really static, what changed to cause the spark to happen when it did, rather than at some other time? (A cosmic ray would breach the stasis.)
 
 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk  
Rayleigh, Essex UK
 
On 2018-01-07 03:37, Doug Smith wrote:
 
 
  
Hi Ed and Ken,
 
 An ESD event can be produced without any direct addition of charge. It only takes an E field and two conductors near each other as in:
 
 http://emcesd.com/tt2001/tt060101.htm
 
 http://emcesd.com/tt2001/tt050101.htm  
 
 Unobserved discharge not needed and generally is not involved with these type of events. Just a static E field will induce a spark.
 
 
 
 
 -


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Re: [PSES] ESD question

[Ken Javor]

In Doug Smith¹s demo of a spark gap and charged paper cup, there was
movement of charge induced in the point closest the cup, and that generated
a potential difference across the points.  So even though the total amount
of charge may have been static, there was a change in local charge and hence
potential difference across the points.

Since we are being philosophical here, it seems the same can be said of any
ESD event, if the picture is big enough. That is, walking across a rug,
petting a cat, or whatever activity ³generates² the charge in fact doesn't
generate any charge, it simply separates it and moves it around. Enough
charge separation, we get a potential difference, electric field and
eventual discharge.

So says Coulomb.

Ken Javor
Phone: (256) 650-5261



From: John Woodgate <j...@woodjohn.uk>
Reply-To: John Woodgate <j...@woodjohn.uk>
Date: Sun, 7 Jan 2018 15:00:00 +
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] ESD question

   

 If the charge is still building up, the field is not static in the region
close to whatever the charge is building up on. Just a philosophical point.
 
 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
Rayleigh, Essex UK
 
On 2018-01-07 14:28, Ken Javor wrote:
 
 
>  Re: [PSES] ESD question Cortland: Faraday Law purely inductive coupling from
> an ESD event doesn't cause potentials that breakdown dielectric barriers; it
> induces potentials that cause bit shifts.  But to answer John Woodgate¹s
> question literally, enough charge buildup with some capacitance eventually
> yields a potential high enough to cause dielectric breakdown. Since that is
> basic, I assume I misinterpreted his post.
>  
>  Ken Javor
>  Phone: (256) 650-5261
>  
>  
>  
> 
> From: Cortland Richmond <k...@earthlink.net> <mailto:k...@earthlink.net>
>  Reply-To: Cortland Richmond <k...@earthlink.net> <mailto:k...@earthlink.net>
>  Date: Sun, 7 Jan 2018 06:23:07 -0500
>  To: <EMC-PSTC@LISTSERV.IEEE.ORG> <mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
>  Subject: Re: [PSES] ESD question
>  
>  Induction; I once saw motherboard testers shut down systems under test by
> just walking away from the work table at lunchtime.  Sliding across the cloth
> chair seats generated a charge, and walking away biased the motherboards and
> shut everything down.
>  
>  (They didn't have the funds for antistatic protection ­ so for a few months,
> we had them spraying the chairs with a solution of water and detergent. You
> could tell who worked there because the seats of their pants were wet...)
>  
>  
>  Cortland Richmond
>   
>> -Original Message-
>>  From: John Woodgate
>>  Sent: Jan 7, 2018 4:10 AM
>>  To: EMC-PSTC@LISTSERV.IEEE.ORG
>>  Subject: Re: [PSES] ESD question
>>  
>>   
>>  
>>  Philosophical issue there. If the field is really static, what changed to
>> cause the spark to happen when it did, rather than at some other time? (A
>> cosmic ray would breach the stasis.)
>>   
>>   
>>  John Woodgate OOO-Own Opinions Only
>>  J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
>> <http://www.woodjohn.uk>
>>  Rayleigh, Essex UK
>>   
>>  On 2018-01-07 03:37, Doug Smith wrote:
>>   
>>   
>>   
>>>   
>>>  Hi Ed and Ken,
>>>   
>>>   An ESD event can be produced without any direct addition of charge. It
>>> only takes an E field and two conductors near each other as in:
>>>   
>>>   http://emcesd.com/tt2001/tt060101.htm
>>>   
>>>   http://emcesd.com/tt2001/tt050101.htm
>>> <http://emcesd.com/tt2001/tt060101.htm>
>>>   
>>>   Unobserved discharge not needed and generally is not involved with these
>>> type of events. Just a static E field will induce a spark.
>>>   
>>>   
>>>   
>>>  
>>   
>>   -
>> 
>>  
>>  This message is from the IEEE Product Safety Engineering Society emc-pstc
>> discussion list. To post a message to the list, send your e-mail to
>> <emc-p...@ieee.org> <mailto:emc-p...@ieee.org>
>>  
>>  All emc-pstc postings are archived and searchable on the web at:
>> http://www.ieee-pses.org/emc-pstc.html
>>  
>>  Attachments are not permitted but the IEEE PSES Online Communities site at
>> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
>> formats), large files, etc.
>>  
>>  Website:  htt

Re: [PSES] ESD question

[John Woodgate]

Agreed. Not very static.

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-01-07 15:15, Ken Javor wrote:
Re: [PSES] ESD question If the charge were truly static, and the 
charged surface topology were truly static, then things should remain 
static. But in the case history that opened this thread, I was in 
constant motion.  If the field were on the edge of causing a 
breakdown, then some slight movement on my part could be the trigger, 
moving two separate surfaces slightly closer together. And also 
because I was moving, it could have been a combination of moving two 
separate dielectric surfaces closer together, and continuing to 
increase charge build-up.


Ken Javor
Phone: (256) 650-5261




*From: *John Woodgate <j...@woodjohn.uk>
*Reply-To: *John Woodgate <j...@woodjohn.uk>
*Date: *Sun, 7 Jan 2018 15:00:00 +
*To: *<EMC-PSTC@LISTSERV.IEEE.ORG>
*Subject: *Re: [PSES] ESD question



 If the charge is still building up, the field is not static in the 
region close to whatever the charge is building up on. Just a 
philosophical point.



John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> 
<http://www.woodjohn.uk>

Rayleigh, Essex UK

On 2018-01-07 14:28, Ken Javor wrote:


Re: [PSES] ESD question Cortland: Faraday Law purely inductive
coupling from an ESD event doesn't cause potentials that breakdown
dielectric barriers; it induces potentials that cause bit shifts.
 But to answer John Woodgate’s question literally, enough charge
buildup with some capacitance eventually yields a potential high
enough to cause dielectric breakdown. Since that is basic, I
assume I misinterpreted his post.

 Ken Javor
 Phone: (256) 650-5261




*From: *Cortland Richmond <k...@earthlink.net>
<mailto:k...@earthlink.net> <mailto:k...@earthlink.net>
*Reply-To: *Cortland Richmond <k...@earthlink.net>
<mailto:k...@earthlink.net> <mailto:k...@earthlink.net>
*Date: *Sun, 7 Jan 2018 06:23:07 -0500
*To: *<EMC-PSTC@LISTSERV.IEEE.ORG>
<mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
<mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
*Subject: *Re: [PSES] ESD question

 Induction; I once saw motherboard testers shut down systems under
test by just walking away from the work table at lunchtime.
 Sliding across the cloth chair seats generated a charge, and
walking away biased the motherboards and shut everything down.

 (They didn't have the funds for antistatic protection – so for a
few months, we had them spraying the chairs with a solution of
water and detergent. You could tell who worked there because the
seats of their pants were wet...)


 Cortland Richmond

-Original Message-
 From: John Woodgate
 Sent: Jan 7, 2018 4:10 AM
 To: EMC-PSTC@LISTSERV.IEEE.ORG
 Subject: Re: [PSES] ESD question



 Philosophical issue there. If the field is really static,
what changed to cause the spark to happen when it did, rather
than at some other time? (A cosmic ray would breach the stasis.)


 John Woodgate OOO-Own Opinions Only
 J M Woodgate and Associates www.woodjohn.uk
<http://www.woodjohn.uk> <http://www.woodjohn.uk>
<http://www.woodjohn.uk> <http://www.woodjohn.uk>
 Rayleigh, Essex UK

 On 2018-01-07 03:37, Doug Smith wrote:




 Hi Ed and Ken,

  An ESD event can be produced without any direct addition
of charge. It only takes an E field and two conductors
near each other as in:

http://emcesd.com/tt2001/tt060101.htm

http://emcesd.com/tt2001/tt050101.htm
<http://emcesd.com/tt2001/tt060101.htm>
<http://emcesd.com/tt2001/tt060101.htm>

  Unobserved discharge not needed and generally is not
involved with these type of events. Just a static E field
will induce a spark.





  -


 This message is from the IEEE Product Safety Engineering
Society emc-pstc discussion list. To post a message to the
list, send your e-mail to <emc-p...@ieee.org>
<mailto:emc-p...@ieee.org> <mailto:emc-p...@ieee.org>

 All emc-pstc postings are archived and searchable on the web
at: http://www.ieee-pses.org/emc-pstc.html

 Attachments are not permitted but the IEEE PSES Online
Communities site at http://product-compliance.oc.ieee.org/ can
be used for graphics (in well-used formats), large

Re: [PSES] ESD question

[Ken Javor]

If the charge were truly static, and the charged surface topology were truly
static, then things should remain static. But in the case history that
opened this thread, I was in constant motion.  If the field were on the edge
of causing a breakdown, then some slight movement on my part could be the
trigger, moving two separate surfaces slightly closer together. And also
because I was moving, it could have been a combination of moving two
separate dielectric surfaces closer together, and continuing to increase
charge build-up. 

Ken Javor
Phone: (256) 650-5261




From: John Woodgate <j...@woodjohn.uk>
Reply-To: John Woodgate <j...@woodjohn.uk>
Date: Sun, 7 Jan 2018 15:00:00 +
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] ESD question

   

 If the charge is still building up, the field is not static in the region
close to whatever the charge is building up on. Just a philosophical point.
 
 
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
Rayleigh, Essex UK
 
On 2018-01-07 14:28, Ken Javor wrote:
 
 
>  Re: [PSES] ESD question Cortland: Faraday Law purely inductive coupling from
> an ESD event doesn't cause potentials that breakdown dielectric barriers; it
> induces potentials that cause bit shifts.  But to answer John Woodgate¹s
> question literally, enough charge buildup with some capacitance eventually
> yields a potential high enough to cause dielectric breakdown. Since that is
> basic, I assume I misinterpreted his post.
>  
>  Ken Javor
>  Phone: (256) 650-5261
>  
>  
>  
> 
> From: Cortland Richmond <k...@earthlink.net> <mailto:k...@earthlink.net>
>  Reply-To: Cortland Richmond <k...@earthlink.net> <mailto:k...@earthlink.net>
>  Date: Sun, 7 Jan 2018 06:23:07 -0500
>  To: <EMC-PSTC@LISTSERV.IEEE.ORG> <mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
>  Subject: Re: [PSES] ESD question
>  
>  Induction; I once saw motherboard testers shut down systems under test by
> just walking away from the work table at lunchtime.  Sliding across the cloth
> chair seats generated a charge, and walking away biased the motherboards and
> shut everything down.
>  
>  (They didn't have the funds for antistatic protection ­ so for a few months,
> we had them spraying the chairs with a solution of water and detergent. You
> could tell who worked there because the seats of their pants were wet...)
>  
>  
>  Cortland Richmond
>   
>> -Original Message-
>>  From: John Woodgate
>>  Sent: Jan 7, 2018 4:10 AM
>>  To: EMC-PSTC@LISTSERV.IEEE.ORG
>>  Subject: Re: [PSES] ESD question
>>  
>>   
>>  
>>  Philosophical issue there. If the field is really static, what changed to
>> cause the spark to happen when it did, rather than at some other time? (A
>> cosmic ray would breach the stasis.)
>>   
>>   
>>  John Woodgate OOO-Own Opinions Only
>>  J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
>> <http://www.woodjohn.uk>
>>  Rayleigh, Essex UK
>>   
>>  On 2018-01-07 03:37, Doug Smith wrote:
>>   
>>   
>>   
>>>   
>>>  Hi Ed and Ken,
>>>   
>>>   An ESD event can be produced without any direct addition of charge. It
>>> only takes an E field and two conductors near each other as in:
>>>   
>>>   http://emcesd.com/tt2001/tt060101.htm
>>>   
>>>   http://emcesd.com/tt2001/tt050101.htm
>>> <http://emcesd.com/tt2001/tt060101.htm>
>>>   
>>>   Unobserved discharge not needed and generally is not involved with these
>>> type of events. Just a static E field will induce a spark.
>>>   
>>>   
>>>   
>>>  
>>   
>>   -
>> 
>>  
>>  This message is from the IEEE Product Safety Engineering Society emc-pstc
>> discussion list. To post a message to the list, send your e-mail to
>> <emc-p...@ieee.org> <mailto:emc-p...@ieee.org>
>>  
>>  All emc-pstc postings are archived and searchable on the web at:
>> http://www.ieee-pses.org/emc-pstc.html
>>  
>>  Attachments are not permitted but the IEEE PSES Online Communities site at
>> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
>> formats), large files, etc.
>>  
>>  Website:  http://www.ieee-pses.org/
>>  Instructions:  http://www.ieee-pses.org/list.html (including how to
>> unsubscribe) <http://www.ieee-pses.org/list.html>
>>  List rules: http://www.ieee-pses.org/listrules.html
>>  
>>  For help, send mail to t

Re: [PSES] ESD question

[John Woodgate]

 If the charge is still building up, the field is not static in the 
region close to whatever the charge is building up on. Just a 
philosophical point.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-01-07 14:28, Ken Javor wrote:
Re: [PSES] ESD question Cortland: Faraday Law purely inductive 
coupling from an ESD event doesn't cause potentials that breakdown 
dielectric barriers; it induces potentials that cause bit shifts.  But 
to answer John Woodgate’s question literally, enough charge buildup 
with some capacitance eventually yields a potential high enough to 
cause dielectric breakdown. Since that is basic, I assume I 
misinterpreted his post.


Ken Javor
Phone: (256) 650-5261



*From: *Cortland Richmond <k...@earthlink.net>
*Reply-To: *Cortland Richmond <k...@earthlink.net>
*Date: *Sun, 7 Jan 2018 06:23:07 -0500
*To: *<EMC-PSTC@LISTSERV.IEEE.ORG>
*Subject: *Re: [PSES] ESD question

Induction; I once saw motherboard testers shut down systems under test 
by just walking away from the work table at lunchtime.  Sliding across 
the cloth chair seats generated a charge, and walking away biased the 
motherboards and shut everything down.


(They didn't have the funds for antistatic protection – so for a few 
months, we had them spraying the chairs with a solution of water and 
detergent. You could tell who worked there because the seats of their 
pants were wet...)



Cortland Richmond

-Original Message-
From: John Woodgate
Sent: Jan 7, 2018 4:10 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question



Philosophical issue there. If the field is really static, what
changed to cause the spark to happen when it did, rather than at
some other time? (A cosmic ray would breach the stasis.)


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
<http://www.woodjohn.uk> <http://www.woodjohn.uk>
Rayleigh, Essex UK

On 2018-01-07 03:37, Doug Smith wrote:



Hi Ed and Ken,

 An ESD event can be produced without any direct addition of
charge. It only takes an E field and two conductors near each
other as in:

http://emcesd.com/tt2001/tt060101.htm

http://emcesd.com/tt2001/tt050101.htm
<http://emcesd.com/tt2001/tt060101.htm>
<http://emcesd.com/tt2001/tt060101.htm>

 Unobserved discharge not needed and generally is not involved
with these type of events. Just a static E field will induce a
spark.




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Re: [PSES] ESD question

[Ken Javor]

Cortland: Faraday Law purely inductive coupling from an ESD event doesn't
cause potentials that breakdown dielectric barriers; it induces potentials
that cause bit shifts.  But to answer John Woodgate¹s question literally,
enough charge buildup with some capacitance eventually yields a potential
high enough to cause dielectric breakdown. Since that is basic, I assume I
misinterpreted his post.

Ken Javor
Phone: (256) 650-5261



From: Cortland Richmond <k...@earthlink.net>
Reply-To: Cortland Richmond <k...@earthlink.net>
Date: Sun, 7 Jan 2018 06:23:07 -0500
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] ESD question

Induction; I once saw motherboard testers shut down systems under test by
just walking away from the work table at lunchtime.  Sliding across the
cloth chair seats generated a charge, and walking away biased the
motherboards and shut everything down.

(They didn't have the funds for antistatic protection ­ so for a few months,
we had them spraying the chairs with a solution of water and detergent. You
could tell who worked there because the seats of their pants were wet...)


Cortland Richmond
> -Original Message-
> From: John Woodgate
> Sent: Jan 7, 2018 4:10 AM
> To: EMC-PSTC@LISTSERV.IEEE.ORG
> Subject: Re: [PSES] ESD question
> 
>  
> 
> Philosophical issue there. If the field is really static, what changed to
> cause the spark to happen when it did, rather than at some other time? (A
> cosmic ray would breach the stasis.)
>  
>  
> John Woodgate OOO-Own Opinions Only
> J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk>
> Rayleigh, Essex UK
>  
> On 2018-01-07 03:37, Doug Smith wrote:
>  
>  
>>   
>> Hi Ed and Ken,
>>  
>>  An ESD event can be produced without any direct addition of charge. It only
>> takes an E field and two conductors near each other as in:
>>  
>>  http://emcesd.com/tt2001/tt060101.htm
>>  
>>  http://emcesd.com/tt2001/tt050101.htm
>> <http://emcesd.com/tt2001/tt060101.htm>
>>  
>>  Unobserved discharge not needed and generally is not involved with these
>> type of events. Just a static E field will induce a spark.
>>  
>>  
>>  
>  
>  -
> 
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> <emc-p...@ieee.org>
> 
> All emc-pstc postings are archived and searchable on the web at:
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> 
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
> formats), large files, etc.
> 
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Re: [PSES] ESD question

[Cortland Richmond]

Induction; I once saw motherboard testers shut down systems under test by just walking away from the work table at lunchtime.  Sliding across the cloth chair seats generated a charge, and walking away biased the motherboards and shut everything down.(They didn't have the funds for antistatic protection – so for a few months, we had them spraying the chairs with a solution of water and detergent. You could tell who worked there because the seats of their pants were wet...)Cortland Richmond-Original Message-
From: John Woodgate <j...@woodjohn.uk>
Sent: Jan 7, 2018 4:10 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question


  

  
  
Philosophical issue there. If the field is really static, what
  changed to cause the spark to happen when it did, rather than at
  some other time? (A cosmic ray would breach the stasis.)

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK
On 2018-01-07 03:37, Doug Smith wrote:


  
  Hi Ed and Ken,

An ESD event can be produced without any direct addition of
charge. It only takes an E field and two conductors near each
other as in:

http://emcesd.com/tt2001/tt060101.htm
  
  http://emcesd.com/tt2001/tt050101.htm

Unobserved discharge not needed and generally is not involved
with these type of events. Just a static E field will induce a
spark.
  
  


  

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Re: [PSES] ESD question

[John Woodgate]

Philosophical issue there. If the field is really static, what changed 
to cause the spark to happen when it did, rather than at some other 
time? (A cosmic ray would breach the stasis.)


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-01-07 03:37, Doug Smith wrote:

Hi Ed and Ken,

An ESD event can be produced without any direct addition of charge. It 
only takes an E field and two conductors near each other as in:


http://emcesd.com/tt2001/tt060101.htm

http://emcesd.com/tt2001/tt050101.htm

Unobserved discharge not needed and generally is not involved with 
these type of events. Just a static E field will induce a spark.





-

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list. To post a message to the list, send your e-mail to 

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Re: [PSES] ESD question

[Ken Javor]

What Ed said made sense in that the ear canal is going to allow a breakdown
at a lower potential than elsewhere, so even though the potential difference
between phone/earbuds and me was perhaps not as a large as between me and
some other object completely isolated from me, it was enough, and as many
have noted, the inner ear is going to be more sensitive than other parts of
the body that are dryer and less sensitive.

Ken Javor
Phone: (256) 650-5261



From: Doug Smith <d...@emcesd.com>
Reply-To: <d...@emcesd.com>
Date: Sat, 6 Jan 2018 22:37:58 -0500
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] ESD question

Hi Ed and Ken,

An ESD event can be produced without any direct addition of charge. It only
takes an E field and two conductors near each other as in:

http://emcesd.com/tt2001/tt060101.htm

http://emcesd.com/tt2001/tt050101.htm
<http://emcesd.com/tt2001/tt060101.htm>

Unobserved discharge not needed and generally is not involved with these
type of events. Just a static E field will induce a spark.

Doug 



On Sun, 7 Jan 2018 00:17:35 +, Edward Price  wrote:

 
Ken:
My guess would be that there was an unobserved discharge from the fabric to
the dangling earphone cord, which then discharged into your body capacitance
in your ear canals (which were extra conductive due to trapped moisture
filling the ear canals and the earbud orifices). I wonder if a vapor of
perspiration and earwax will fluoresce?

Ed Price
WB6WSN
Chula Vista, CA USA

From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Friday, January 05, 2018 6:21 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] ESD question
Just curiosity.

Spent a week in the cold frozen north. Single Fahrenheit digits (above and
below zero) outside, snow on the ground, 70 degrees inside ­ dry air. Was
able to generate some pretty decent lightning simulations walking around and
especially stripping a bed that had some sort of fuzzy (no doubt synthetic
material) blanket. While stripping the bed, I was listening to a podcast on
an iPhone, through wired earbuds. I could hear the discharges through the
earbuds. That was some sort of interference, but not the question of
interest here. What was interesting is that the bigger sparks not only
zapped where I made contact (typically hands) but also from the earbuds to
my inner ear (ouch)! That¹s not what I said, but close enough.

The iPhone was in a leather pouch suspended from by belt. The hook around
the belt was metal, the belt was leather, and there were (denim cotton)
pants between the hook on the inside of the belt and my skin. To my
understanding, the iPhone and earbuds should have been at near or the same
potential I was, and even if not, it was certainly no sort of ground ­
completely isolated from anything except me.

So the question is why was there such a potential difference between iPhone
and earbuds and me that my ears were zapped?

Ken Javor
Phone: (256) 650-5261
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Re: [PSES] ESD question

[Doug Smith]

Hi Ed and Ken,

An ESD event can be produced without any direct addition of charge. It only 
takes an E field and two conductors near each other as in:

http://emcesd.com/tt2001/tt060101.htm

http://emcesd.com/tt2001/tt050101.htm

Unobserved discharge not needed and generally is not involved with these type 
of events. Just a static E field will induce a spark.

Doug








On Sun, 7 Jan 2018 00:17:35 +, Edward Price  wrote:

 








Ken:



My guess would be that there was an unobserved discharge from the fabric to the 
dangling earphone cord, which then discharged into your body capacitance in 
your ear canals (which were extra conductive due to trapped moisture filling 
the ear canals and the earbud orifices). I wonder if a vapor of perspiration 
and earwax will fluoresce?




Ed Price
WB6WSN
Chula Vista, CA USA






From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Friday, January 05, 2018 6:21 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] ESD question





Just curiosity.

Spent a week in the cold frozen north. Single Fahrenheit digits (above and 
below zero) outside, snow on the ground, 70 degrees inside – dry air. Was able 
to generate some pretty decent lightning simulations walking around and 
especially stripping a bed that had some sort of fuzzy (no doubt synthetic 
material) blanket. While stripping the bed, I was listening to a podcast on an 
iPhone, through wired earbuds. I could hear the discharges through the earbuds. 
That was some sort of interference, but not the question of interest here. What 
was interesting is that the bigger sparks not only zapped where I made contact 
(typically hands) but also from the earbuds to my inner ear (ouch)! That’s not 
what I said, but close enough.

The iPhone was in a leather pouch suspended from by belt. The hook around the 
belt was metal, the belt was leather, and there were (denim cotton) pants 
between the hook on the inside of the belt and my skin. To my understanding, 
the iPhone and earbuds should have been at near or the same potential I was, 
and even if not, it was certainly no sort of ground – completely isolated from 
anything except me.

So the question is why was there such a potential difference between iPhone and 
earbuds and me that my ears were zapped?

Ken Javor
Phone: (256) 650-5261

-


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J

[PSES] ESD question

[Edward Price]

Ken:

My guess would be that there was an unobserved discharge from the fabric to the 
dangling earphone cord, which then discharged into your body capacitance in 
your ear canals (which were extra conductive due to trapped moisture filling 
the ear canals and the earbud orifices). I wonder if a vapor of perspiration 
and earwax will fluoresce?

Ed Price
WB6WSN
Chula Vista, CA USA

From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Friday, January 05, 2018 6:21 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: [PSES] ESD question

Just curiosity.

Spent a week in the cold frozen north. Single Fahrenheit digits (above and 
below zero) outside, snow on the ground, 70 degrees inside - dry air.  Was able 
to generate some pretty decent lightning simulations walking around and 
especially stripping a bed that had some sort of fuzzy (no doubt synthetic 
material) blanket.  While stripping the bed, I was listening to a podcast on an 
iPhone, through wired earbuds.  I could hear the discharges through the 
earbuds. That was some sort of interference, but not the question of interest 
here. What was interesting is that the bigger sparks not only zapped where I 
made contact (typically hands) but also from the earbuds to my inner ear 
(ouch)!  That's not what I said, but close enough.

The iPhone was in a leather pouch suspended from by belt. The hook around the 
belt was metal, the belt was leather, and there were (denim cotton) pants 
between the hook on the inside of the belt and my skin.  To my understanding, 
the iPhone and earbuds should have been at near or the same potential I was, 
and even if not, it was certainly no sort of ground - completely isolated from 
anything except me.

So the question is why was there such a potential difference between iPhone and 
earbuds and me that my ears were zapped?

Ken Javor
Phone: (256) 650-5261
-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
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Re: [PSES] ESD question

[Douglas Smith]

ESD in Britain! I think of wet when I think of Britain..Now the American 
Southwest desert, where I live, is the ESD capital of the world, even more than 
cold places as it is drier here and the dryness lasts most of the year, except 
August when the dew point gets up into the 50s and once in a while to 60 F.
I run miles and miles mid-day at 110 degrees F all the time here in the summer 
and I am not hot because the dew point is often 0-10 degrees F. My skin is 
cool. Once in a water fight (popular in the desert) at 95 degrees F, I was 
actually shivering because the dew point was near zero F!
My mouse pad is cut from an ESD dissipative mat and is grounded. When I put the 
key in the office door in the morning I often get a 10-15 kV discharge!
If your product works here, in Boulder City, NV, it will work anywhere! We have 
the world's largest ESD testing lab, the whole city.

Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: 
d...@dsmith.org Website: http://dsmith.org
On Sat, Jan 6, 2018 at 10:38, John Allen 
<09cc677f395b-dmarc-requ...@ieee.org> wrote:
This is a close parallel to the scenario where some gets a “shock” from the 
very small amount of residual stored energy in an appliance filter which has no 
bleeder resistors and is fitted on the supply side of the Mains ON/OFF switch.



It “wakes them up” but does little actual harm – unless, of course, they fall 
over/drop something on a foot, cut a finger with a knife and so on J Then, of 
course, there may be attempted legal action – which, is, I guess, a minefield 
against which to defend if you are the manufacturer /supplier!



John E Allen

W.London, UK.



From: Douglas Smith [mailto:d...@emcesd.com]
Sent: 06 January 2018 18:28
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question



I have had this happen to me using a conventional telephone handset as I rose 
from sitting on a bed. The charge available then was from the full capacitance 
of my body as opposed to the capacitance between the iPhone and the body.



This has been going on for as many years as there have been telephones and 
headsets, I have been involved in a number of studies and lawsuits, some while 
at AR Bell Labs and some on my own since then. In general, I believe lay 
people think that have been harmed when that is very unlikely, there just isn't 
enough energy. But what energy there is, finds itself applied to a sensitive 
part of the body.

Doug Smith

Sent from my iPhone

IPhone: 408-858-4528

Office: 702-570-6108

Email: d...@dsmith.org [d...@dsmith.org]

Website: http://dsmith.org [http://dsmith.org]



On Sat, Jan 6, 2018 at 10:15, Adam Dixon < lanterna.viri...@gmail.com 
[lanterna.viri...@gmail.com] > wrote:

Doug,



How significant are differences between the telephone/radar operators cases and 
Ken's experience? Equipment capacitances (higher pF for telephone/radar 
operators), discharge location and voltage (Ken's in-ear ear buds vs. "on/over 
ear" for operators), wire lengths and floating vs. earthed configurations? Both 
deal with energy transfer to/from cells that are likely more sensitive 
(electrically/neurally/perceptually) than the human hand. Sounds (pun intended) 
like an interesting neuroscience topic!



Maybe this could be an occasional benefit to not having a 3.5mm audio jack on a 
hand set.



And this probably isn't a good idea for a new experiment at your workshops. ;-)





Cheers,

Adam in Atlanta





On Sat, Jan 6, 2018 at 2:48 AM, Douglas Smith < d...@emcesd.com 
[d...@emcesd.com] > wrote:

Thus is a common occurrence. The iPhone was not actually connected to you so 
the large E field induced a different charge on you than on the phone and hence 
the discharge through your ear (the lowest breakdown between the iPhond and you.



Such discharges have led to claims of injury that ended up in court. Telephone 
operators and radar operators (such as in air traffic control) experience this 
effect. The first case I was involved with was 20 years ago and since have 
provided expertise to lawyers on legal cases involving this effect. The 
discharge is not dangerous, but people have been convinced they were nearly 
electrocuted and have been hauled off to the hospital on a stretcher!



Doug Smith

Sent from my iPhone

IPhone: 408-858-4528 [tel:(408)%20858-4528]

Office: 702-570-6108 [tel:(702)%20570-6108]

Email: d...@dsmith.org [d...@dsmith.org]

Website: http://dsmith.org [http://dsmith.org]



On Fri, Jan 5, 2018 at 18:21, Ken Javor < ken.ja...@emccompliance.com 
[ken.ja...@emccompliance.com] > wrote:

Just curiosity.

Spent a week in the cold frozen north. Single Fahrenheit digits (above and 
below zero) outside, snow on the ground, 70 degrees inside – dry air. Was able 
to generate some pretty decent lightning simulations walking around and 
especially stripping a bed that had some sort of fuzzy (no doubt synthetic 
material) blanket. While stripping the

Re: [PSES] ESD question

[John Allen]

This is a close parallel to the scenario where some gets a “shock” from the 
very small amount of residual stored energy in an appliance filter which has no 
bleeder resistors and is fitted on the supply side of the Mains ON/OFF switch. 

 

It “wakes them up” but does little actual harm – unless, of course, they fall 
over/drop something on a foot, cut a finger with a knife and so on J Then, of 
course, there may be attempted legal action – which, is, I guess, a minefield 
against which to defend if you are the manufacturer /supplier!

 

John E Allen

W.London, UK.

 

From: Douglas Smith [mailto:d...@emcesd.com] 
Sent: 06 January 2018 18:28
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] ESD question

 

  
<https://tr.cloudmagic.com/h/v6/emailtag/tag/2.0/1515263292/1f1617f6804b53a4713f5023a09a661a/1/e6b2e6caabff23ac8328d6a5dc39f227/39feccaef3f24eadcf81b440d32e4ebf/4a2f0d9f9edf6d707780b6838cf331be/newton.gif>
 I have had this happen to me using a conventional telephone handset as I rose 
from sitting on a bed. The charge available then was from the full capacitance 
of my body as opposed to the capacitance between the iPhone and the body.

 

This has been going on for as many years as there have been telephones and 
headsets, I have been involved in a number of studies and lawsuits, some while 
at AR Bell Labs and some on my own since then. In general, I believe lay 
people think that have been harmed when that is very unlikely, there just isn't 
enough energy. But what energy there is, finds itself applied to a sensitive 
part of the body.

Doug Smith

Sent from my iPhone

IPhone:  408-858-4528

Office:702-570-6108

Email: d...@dsmith.org

Website: http://dsmith.org

 

On Sat, Jan 6, 2018 at 10:15, Adam Dixon <lanterna.viri...@gmail.com> wrote:

Doug,

 

How significant are differences between the telephone/radar operators cases and 
Ken's experience? Equipment capacitances (higher pF for telephone/radar 
operators), discharge location and voltage (Ken's in-ear ear buds vs. "on/over 
ear" for operators), wire lengths and floating vs. earthed configurations? Both 
deal with energy transfer to/from cells that are likely more sensitive 
(electrically/neurally/perceptually) than the human hand. Sounds (pun intended) 
like an interesting neuroscience topic!

 

Maybe this could be an occasional benefit to not having a 3.5mm audio jack on a 
hand set. 

 

And this probably isn't a good idea for a new experiment at your workshops. ;-) 

 

 

Cheers,

Adam in Atlanta

 

 

On Sat, Jan 6, 2018 at 2:48 AM, Douglas Smith <d...@emcesd.com> wrote:

Thus is a common occurrence. The iPhone was not actually connected to you so 
the large E field induced a different charge on you than on the phone and hence 
the discharge through your ear (the lowest breakdown between the iPhond and you.

 

Such discharges have led to claims of injury that ended up in court. Telephone 
operators and radar operators (such as in air traffic control) experience this 
effect. The first case I was involved with was 20 years ago and since have 
provided expertise to lawyers on legal cases involving this effect. The 
discharge is not dangerous, but people have been convinced they were nearly 
electrocuted and have been hauled off to the hospital on a stretcher!

 

Doug Smith

Sent from my iPhone

IPhone: 408-858-4528 <tel:(408)%20858-4528> 

Office: 702-570-6108 <tel:(702)%20570-6108> 

Email: d...@dsmith.org

Website: http://dsmith.org

 

On Fri, Jan 5, 2018 at 18:21, Ken Javor <ken.ja...@emccompliance.com> wrote:

Just curiosity.

Spent a week in the cold frozen north. Single Fahrenheit digits (above and 
below zero) outside, snow on the ground, 70 degrees inside – dry air. Was able 
to generate some pretty decent lightning simulations walking around and 
especially stripping a bed that had some sort of fuzzy (no doubt synthetic 
material) blanket. While stripping the bed, I was listening to a podcast on an 
iPhone, through wired earbuds. I could hear the discharges through the earbuds. 
That was some sort of interference, but not the question of interest here. What 
was interesting is that the bigger sparks not only zapped where I made contact 
(typically hands) but also from the earbuds to my inner ear (ouch)! That’s not 
what I said, but close enough.

The iPhone was in a leather pouch suspended from by belt. The hook around the 
belt was metal, the belt was leather, and there were (denim cotton) pants 
between the hook on the inside of the belt and my skin. To my understanding, 
the iPhone and earbuds should have been at near or the same potential I was, 
and even if not, it was certainly no sort of ground – completely isolated from 
anything except me.

So the question is why was there such a potential difference between iPhone and 
earbuds and me that my ears were zapped?

Ken Javor
Phone: (256) 650-5261 <tel:(256)%20650-5261> 

-
--

Re: [PSES] ESD question

[Douglas Smith]

I have had this happen to me using a conventional telephone handset as I rose 
from sitting on a bed. The charge available then was from the full capacitance 
of my body as opposed to the capacitance between the iPhone and the body.
This has been going on for as many years as there have been telephones and 
headsets, I have been involved in a number of studies and lawsuits, some while 
at AR Bell Labs and some on my own since then. In general, I believe lay 
people think that have been harmed when that is very unlikely, there just isn't 
enough energy. But what energy there is, finds itself applied to a sensitive 
part of the body.

Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: 
d...@dsmith.org Website: http://dsmith.org
On Sat, Jan 6, 2018 at 10:15, Adam Dixon  wrote:
Doug,
How significant are differences between the telephone/radar operators cases and 
Ken's experience? Equipment capacitances (higher pF for telephone/radar 
operators), discharge location and voltage (Ken's in-ear ear buds vs. "on/over 
ear" for operators), wire lengths and floating vs. earthed configurations? Both 
deal with energy transfer to/from cells that are likely more sensitive 
(electrically/neurally/perceptually) than the human hand. Sounds (pun intended) 
like an interesting neuroscience topic!

Maybe this could be an occasional benefit to not having a 3.5mm audio jack on a 
hand set.

And this probably isn't a good idea for a new experiment at your workshops. ;-)

Cheers, Adam in Atlanta


On Sat, Jan 6, 2018 at 2:48 AM, Douglas Smith < d...@emcesd.com 
[d...@emcesd.com] > wrote:
Thus is a common occurrence. The iPhone was not actually connected to you so 
the large E field induced a different charge on you than on the phone and hence 
the discharge through your ear (the lowest breakdown between the iPhond and you.
Such discharges have led to claims of injury that ended up in court. Telephone 
operators and radar operators (such as in air traffic control) experience this 
effect. The first case I was involved with was 20 years ago and since have 
provided expertise to lawyers on legal cases involving this effect. The 
discharge is not dangerous, but people have been convinced they were nearly 
electrocuted and have been hauled off to the hospital on a stretcher!
Doug Smith Sent from my iPhone IPhone: 408-858-4528 [tel:(408)%20858-4528] 
Office: 702-570-6108 [tel:(702)%20570-6108] Email: d...@dsmith.org 
[d...@dsmith.org] Website: http://dsmith.org [http://dsmith.org]
On Fri, Jan 5, 2018 at 18:21, Ken Javor < ken.ja...@emccompliance.com 
[ken.ja...@emccompliance.com] > wrote:
Just curiosity.

Spent a week in the cold frozen north. Single Fahrenheit digits (above and 
below zero) outside, snow on the ground, 70 degrees inside – dry air. Was able 
to generate some pretty decent lightning simulations walking around and 
especially stripping a bed that had some sort of fuzzy (no doubt synthetic 
material) blanket. While stripping the bed, I was listening to a podcast on an 
iPhone, through wired earbuds. I could hear the discharges through the earbuds. 
That was some sort of interference, but not the question of interest here. What 
was interesting is that the bigger sparks not only zapped where I made contact 
(typically hands) but also from the earbuds to my inner ear (ouch)! That’s not 
what I said, but close enough.

The iPhone was in a leather pouch suspended from by belt. The hook around the 
belt was metal, the belt was leather, and there were (denim cotton) pants 
between the hook on the inside of the belt and my skin. To my understanding, 
the iPhone and earbuds should have been at near or the same potential I was, 
and even if not, it was certainly no sort of ground – completely isolated from 
anything except me.

So the question is why was there such a potential difference between iPhone and 
earbuds and me that my ears were zapped?

Ken Javor
Phone: (256) 650-5261 [tel:(256)%20650-5261]
-
-- -- 
This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to < 
emc-p...@ieee.org [emc-p...@ieee.org] >

All emc-pstc postings are archived and searchable on the web at: 
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Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc. ieee.org/ 
[http://product-compliance.oc.ieee.org/] can be used for graphics (in well-used 
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[http://www.ieee-pses.org/listrules.html]

For help, send mail to the list administrators:
Scott Douglas < 

Re: [PSES] ESD question

[Adam Dixon]

Doug,

How significant are differences between the telephone/radar operators cases
and Ken's experience?  Equipment capacitances (higher pF for
telephone/radar operators), discharge location and voltage (Ken's in-ear
ear buds vs. "on/over ear" for operators), wire lengths and floating vs.
earthed configurations?  Both deal with energy transfer to/from cells that
are likely more sensitive (electrically/neurally/perceptually) than the
human hand.   Sounds (pun intended) like an interesting neuroscience topic!

Maybe this could be an occasional benefit to not having a 3.5mm audio jack
on a hand set.

And this probably isn't a good idea for a new experiment at your
workshops.  ;-)


Cheers,
Adam in Atlanta


On Sat, Jan 6, 2018 at 2:48 AM, Douglas Smith  wrote:

> Thus is a common occurrence. The iPhone was not actually connected to you
> so the large E field induced a different charge on you than on the phone
> and hence the discharge through your ear (the lowest breakdown between the
> iPhond and you.
>
> Such discharges have led to claims of injury that ended up in court.
> Telephone operators and radar operators (such as in air traffic control)
> experience this effect. The first case I was involved with was 20 years ago
> and since have provided expertise to lawyers on legal cases involving this
> effect. The discharge is not dangerous, but people have been convinced they
> were nearly electrocuted and have been hauled off to the hospital on a
> stretcher!
>
> Doug Smith
> Sent from my iPhone
> IPhone:  408-858-4528 <(408)%20858-4528>
> Office:702-570-6108 <(702)%20570-6108>
> Email: d...@dsmith.org
> Website: http://dsmith.org
>
> On Fri, Jan 5, 2018 at 18:21, Ken Javor 
> wrote:
>
> Just curiosity.
>
> Spent a week in the cold frozen north. Single Fahrenheit digits (above and
> below zero) outside, snow on the ground, 70 degrees inside – dry air.  Was
> able to generate some pretty decent lightning simulations walking around
> and especially stripping a bed that had some sort of fuzzy (no doubt
> synthetic material) blanket.  While stripping the bed, I was listening to a
> podcast on an iPhone, through wired earbuds.  I could hear the discharges
> through the earbuds. That was some sort of interference, but not the
> question of interest here. What was interesting is that the bigger sparks
> not only zapped where I made contact (typically hands) but also from the
> earbuds to my inner ear (ouch)!  That’s not what I said, but close enough.
>
> The iPhone was in a leather pouch suspended from by belt. The hook around
> the belt was metal, the belt was leather, and there were (denim cotton)
> pants between the hook on the inside of the belt and my skin.  To my
> understanding, the iPhone and earbuds should have been at near or the same
> potential I was, and even if not, it was certainly no sort of ground –
> completely isolated from anything except me.
>
> So the question is why was there such a potential difference between
> iPhone and earbuds and me that my ears were zapped?
>
> Ken Javor
> Phone: (256) 650-5261
> -
> 
>
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to <
> emc-p...@ieee.org>
>
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in
> well-used formats), large files, etc.
>
> Website: http://www.ieee-pses.org/
> Instructions: http://www.ieee-pses.org/list.html (including how to
> unsubscribe) 
> List rules: http://www.ieee-pses.org/listrules.html
>
> For help, send mail to the list administrators:
> Scott Douglas 
> Mike Cantwell 
>
> For policy questions, send mail to:
> Jim Bacher 
> David Heald 
>
> -
> 
>
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to 
> emc-p...@ieee.org
>
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in
> well-used formats), large files, etc.
>
> Website: http://www.ieee-pses.org/
> Instructions: http://www.ieee-pses.org/list.html (including how to
> unsubscribe) 
> List rules: http://www.ieee-pses.org/listrules.html
>
> For help, send mail to the list administrators:
> Scott Douglas sdoug...@ieee.org
> Mike Cantwell mcantw...@ieee.org
>
> For 

Re: [PSES] ESD question

[Ken Javor]

Nothing (legally) actionable happened here, I hope.  I said some things I
shouldn¹t have, but not the first time ­ repeat offender.

Thanks for the explanation.

Ken Javor
Phone: (256) 650-5261




From: Douglas Smith <d...@emcesd.com>
Reply-To: Douglas Smith <d...@emcesd.com>
Date: Fri, 5 Jan 2018 23:48:01 -0800
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] ESD question


 Thus is a common occurrence. The iPhone was not actually connected to you
so the large E field induced a different charge on you than on the phone and
hence the discharge through your ear (the lowest breakdown between the
iPhond and you.

Such discharges have led to claims of injury that ended up in court.
Telephone operators and radar operators (such as in air traffic control)
experience this effect. The first case I was involved with was 20 years ago
and since have provided expertise to lawyers on legal cases involving this
effect. The discharge is not dangerous, but people have been convinced they
were nearly electrocuted and have been hauled off to the hospital on a
stretcher!

Doug Smith
Sent from my iPhone
IPhone:  408-858-4528
Office:702-570-6108
Email: d...@dsmith.org
Website: http://dsmith.org

On Fri, Jan 5, 2018 at 18:21, Ken Javor <ken.ja...@emccompliance.com> wrote:
> ESD question 
> Just curiosity.
> 
> Spent a week in the cold frozen north. Single Fahrenheit digits (above and
> below zero) outside, snow on the ground, 70 degrees inside ­ dry air.  Was
> able to generate some pretty decent lightning simulations walking around and
> especially stripping a bed that had some sort of fuzzy (no doubt synthetic
> material) blanket.  While stripping the bed, I was listening to a podcast on
> an iPhone, through wired earbuds.  I could hear the discharges through the
> earbuds. That was some sort of interference, but not the question of interest
> here. What was interesting is that the bigger sparks not only zapped where I
> made contact (typically hands) but also from the earbuds to my inner ear
> (ouch)!  That¹s not what I said, but close enough.
> 
> The iPhone was in a leather pouch suspended from by belt. The hook around the
> belt was metal, the belt was leather, and there were (denim cotton) pants
> between the hook on the inside of the belt and my skin.  To my understanding,
> the iPhone and earbuds should have been at near or the same potential I was,
> and even if not, it was certainly no sort of ground ­ completely isolated from
> anything except me.
> 
> So the question is why was there such a potential difference between iPhone
> and earbuds and me that my ears were zapped?
> 
> Ken Javor
> Phone: (256) 650-5261
> -
> 
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> <emc-p...@ieee.org>
> 
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
> formats), large files, etc.
> 
> Website:  http://www.ieee-pses.org/
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This message is from the IEEE Product Safety Engineering Soc

Re: [PSES] ESD question

[Douglas Smith]

BTW, indoor humidity is constant in Boulder City, NV as the dewpoint does not 
change much summer to winter. It is often 10 degrees F almost any time of year, 
and conventional air conditioning actually increases indoor relative humidity 
as they do not remove water (dewpoint too low) but cool the air.
If you want to test ESD in the winter in Canada but do not want to brave the 
cold weather, you get the same conditions in Boulder City in June while wearing 
shorts and T-shirt.

Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: 
d...@dsmith.org Website: http://dsmith.org
On Fri, Jan 5, 2018 at 18:21, Ken Javor <ken.ja...@emccompliance.com> wrote:
ESD question Just curiosity.

Spent a week in the cold frozen north. Single Fahrenheit digits (above and 
below zero) outside, snow on the ground, 70 degrees inside – dry air. Was able 
to generate some pretty decent lightning simulations walking around and 
especially stripping a bed that had some sort of fuzzy (no doubt synthetic 
material) blanket. While stripping the bed, I was listening to a podcast on an 
iPhone, through wired earbuds. I could hear the discharges through the earbuds. 
That was some sort of interference, but not the question of interest here. What 
was interesting is that the bigger sparks not only zapped where I made contact 
(typically hands) but also from the earbuds to my inner ear (ouch)! That’s not 
what I said, but close enough.

The iPhone was in a leather pouch suspended from by belt. The hook around the 
belt was metal, the belt was leather, and there were (denim cotton) pants 
between the hook on the inside of the belt and my skin. To my understanding, 
the iPhone and earbuds should have been at near or the same potential I was, 
and even if not, it was certainly no sort of ground – completely isolated from 
anything except me.

So the question is why was there such a potential difference between iPhone and 
earbuds and me that my ears were zapped?

Ken Javor
Phone: (256) 650-5261
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Re: [PSES] ESD question

[Douglas Smith]

Thus is a common occurrence. The iPhone was not actually connected to you so 
the large E field induced a different charge on you than on the phone and hence 
the discharge through your ear (the lowest breakdown between the iPhond and you.
Such discharges have led to claims of injury that ended up in court. Telephone 
operators and radar operators (such as in air traffic control) experience this 
effect. The first case I was involved with was 20 years ago and since have 
provided expertise to lawyers on legal cases involving this effect. The 
discharge is not dangerous, but people have been convinced they were nearly 
electrocuted and have been hauled off to the hospital on a stretcher!
Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: 
d...@dsmith.org Website: http://dsmith.org
On Fri, Jan 5, 2018 at 18:21, Ken Javor <ken.ja...@emccompliance.com> wrote:
ESD question Just curiosity.

Spent a week in the cold frozen north. Single Fahrenheit digits (above and 
below zero) outside, snow on the ground, 70 degrees inside – dry air. Was able 
to generate some pretty decent lightning simulations walking around and 
especially stripping a bed that had some sort of fuzzy (no doubt synthetic 
material) blanket. While stripping the bed, I was listening to a podcast on an 
iPhone, through wired earbuds. I could hear the discharges through the earbuds. 
That was some sort of interference, but not the question of interest here. What 
was interesting is that the bigger sparks not only zapped where I made contact 
(typically hands) but also from the earbuds to my inner ear (ouch)! That’s not 
what I said, but close enough.

The iPhone was in a leather pouch suspended from by belt. The hook around the 
belt was metal, the belt was leather, and there were (denim cotton) pants 
between the hook on the inside of the belt and my skin. To my understanding, 
the iPhone and earbuds should have been at near or the same potential I was, 
and even if not, it was certainly no sort of ground – completely isolated from 
anything except me.

So the question is why was there such a potential difference between iPhone and 
earbuds and me that my ears were zapped?

Ken Javor
Phone: (256) 650-5261
-

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discussion list. To post a message to the list, send your e-mail to < 
emc-p...@ieee.org [emc-p...@ieee.org] >

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http://www.ieee-pses.org/emc-pstc.html [http://www.ieee-pses.org/emc-pstc.html]

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ [http://product-compliance.oc.ieee.org/] 
can be used for graphics (in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/ [http://www.ieee-pses.org/]
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Jim Bacher < j.bac...@ieee.org [j.bac...@ieee.org] >
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[PSES] ESD question

[Ken Javor]

Just curiosity.

Spent a week in the cold frozen north. Single Fahrenheit digits (above and
below zero) outside, snow on the ground, 70 degrees inside ­ dry air.  Was
able to generate some pretty decent lightning simulations walking around and
especially stripping a bed that had some sort of fuzzy (no doubt synthetic
material) blanket.  While stripping the bed, I was listening to a podcast on
an iPhone, through wired earbuds.  I could hear the discharges through the
earbuds. That was some sort of interference, but not the question of
interest here. What was interesting is that the bigger sparks not only
zapped where I made contact (typically hands) but also from the earbuds to
my inner ear (ouch)!  That¹s not what I said, but close enough.

The iPhone was in a leather pouch suspended from by belt. The hook around
the belt was metal, the belt was leather, and there were (denim cotton)
pants between the hook on the inside of the belt and my skin.  To my
understanding, the iPhone and earbuds should have been at near or the same
potential I was, and even if not, it was certainly no sort of ground ­
completely isolated from anything except me.

So the question is why was there such a potential difference between iPhone
and earbuds and me that my ears were zapped?

Ken Javor
Phone: (256) 650-5261


-

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discussion list. To post a message to the list, send your e-mail to 


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Re: [PSES] Safety cost and ESD - My copy of 61000-4-2 found its way back to my desk - I have the ESD question answer thanks.

[McInturff, Gary]

Gary

From: McInturff, Gary [mailto:gary.mcintu...@esterline.com]
Sent: Monday, April 23, 2012 11:37 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] Safety cost and ESD

Given the implementation differences between US/Canada(?) and EU on the medical 
60601-1 standards. EU the June, US June 2013. How are folks handling new 
products being introduced now or in the very near future? Just got a quote back 
and the US certifier wants to charge me twice once for the 2nd edition and then 
to transition to the 3rd edition. I anyone else running aground on this. Seems 
like this should be happening on both sides of the pond - since a CB report to 
3rd edition would run into the second edition enforcement in the US (and maybe 
Canada - I don't know their implementation date).

To be fair - I get good service once I get past the sticker shock and don't 
have any complaints from that standpoint. In fact I enjoy the engineering staff 
I work with.

Different question about ESD.

I have a component we tested on the normal 55024 directed ESD table for a table 
top mounted device. Worked fine, problem is that the customer places this on a 
large metallic roll around pedestal on rubber wheels. When they send it to a 
lab and test it this way there is a problem. I don't have the pedestal so I'm 
trying to simulate with my table and removing the 1 mohm bleeder resistor. 
Between discharges to the table, I ground a braided strap attached to the table 
top to my reference plane below. I get very similar results then. What should 
the braid really look like - should it just be a short, should it have some 
bleed resistance in it. I chose none since the discharge is going to be people 
touching the pedestal or other furniture that is grounded.

What does the standard say about  the VCP and HCP?


Gary McInturff
Reliability/Compliance Engineer








Esterline Interface Technologies

Featuring
ADVANCED INPUT, MEMTRON, and LRE MEDICAL products



600 W. Wilbur Avenue
Coeur d'Alene, ID  83815-9496
Office:208-635-8306
Cell:  509 868 2279
Toll Free: 800-444-5923 X 1238
gary.mcintu...@esterline.commailto:brian.s...@esterline.com


www.esterline.com/interfacetechnologieshttp://www.esterline.com/advancedinput

Technology, Innovation, Performance...



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RE: An ESD question

[Gibling, Vic]

Thank you all for your comments and advice, it is appreciated.

For your interest, the product had gone through approval and though there
were some ESD induced abnormalities these were considered a low risk. It was
the reports from two independent customers regarding a particular failure
mode that led to this investigation. To achieve this particular failure mode
we had to reduce the level to -800V ; I should point out that at higher
levels, other failures were infrequent.

What is probably more 'interesting' is that both customer's method of use
was different, though valid, to the way we had perceived.


As an aside, when working on compliance problems I am often reminded of the
following:

When looking for the light at the end of the tunnel, make sure you are not
in a cave 

Thanks again,

Vic Gibling
Compliance Engineer (in the making)
Marconi Applied Technologies

 

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RE: An ESD question

[Gary McInturff]

Remember at time testing at a manufacturing location down south. Don't 
know if it was humidity but we were the first to know that a rain storm was 
headed our way. There was a dramatic change in the ESD discharge and response 
characteristics before and during the downpour. Same for a trip in Japan - 
which is very humid to start with.
No attempt to explain - just presenting a couple of experiences.
Wasn't really an obstacle, we were easily able to locate and resolve the 
problem regardless of the outside weather. PS neither of the locations had air 
conducting or humidity control so other than physical raindrops we had the same 
temperature and humidity as outdoors.
I dawns on me, that to work out the variability in weather in Japan we 
moved into their sound chamber, that for some reason did have humidity control 
- not a clue why.
Gary

-Original Message-
From: bogdan matoga [mailto:bogda...@pacbell.net]
Sent: Wednesday, June 12, 2002 12:01 PM
To: Gibling, Vic
Cc: emc-p...@majordomo.ieee.org
Subject: Re: An ESD question



Vic:
The ambient relative humidity should have no impact on the performance of the
gut but only on the generation of  static charges. So, to improve the
performance in the field, I would suggest that you increase the R.H. at the
customer site(s) to about 50% which would eliminate the generation of
electrostatic charges and consequently the problems. This will give you time to
work on the equipment to minimize ESD susceptibility.
By the way, lower R.H. also occurs at low tamperatures.
Please let me know how things work out.
Bogdan.

Gibling, Vic wrote:

 Dear Group

 I tried to find David Pommerenke article's in the Journal of ESD on the Web
 but alas no downloadable version was found, so may I ask the group a
 question?

 We have an ESD field failure which is occurring in dry hot countries ( no
 surprise )which can be recreated with an ESD of -800V. In an attempt to get
 a high incidence of discharges we used a dehumidifier to create a dry
 environment. The result was a reduction in discharges.

 Thinking the problem through -now- as a dry atmosphere will encourage the
 production of high level ESD and a humid environment inhibits the charge to
 a lesser level, presumably because it 'leaks' away. Then is it wrong for us
 to attempt to 'dry' the local atmosphere in the hope of gaining consistent
 ESD from an ESD gun, that is to say the more humid the environment the more
 efficiently the discharge will transfer to the victim?

 Incidentally, to add to the thread regarding intermediate level testing for
 ESD and EFT. This exercise has revealed different failure mechanisms at
 different ESD levels.

 Your views would be appreciated.

 Vic Gibling
 Compliance Engineer
 Marconi Applied Technologies



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AW: An ESD question

[Pommerenke, David]

Dear Group,

In dry conditions, not only the charging processes are enhancec, but the 
severity (less risetime, higher peak current) is enhanced in general. For both 
reasons, it is not uncommen to see ESD problems move around the world with the 
local seasons.

Still, I would always try to debug the problem in contact mode. The effect on 
humidity on the electromagnetic properties is in general very small. Aim of the 
debugging should be to identify the traces, nets of PINs that are effected. 

Locally injecting pulses via direct, capacitive, inductive or differential 
injection has prooved to be an effective tool for achieving this.

David




-Ursprüngliche Nachricht-
Von:Gibling, Vic [mailto:vic.gibl...@marconi.com]
Gesendet:   Mi 12.06.2002 02:26
An: emc-p...@majordomo.ieee.org
Cc: 
Betreff:An ESD question



Dear Group 

I tried to find David Pommerenke article's in the Journal of ESD on the Web
but alas no downloadable version was found, so may I ask the group a
question?

We have an ESD field failure which is occurring in dry hot countries ( no
surprise )which can be recreated with an ESD of -800V. In an attempt to get
a high incidence of discharges we used a dehumidifier to create a dry
environment. The result was a reduction in discharges. 

Thinking the problem through -now- as a dry atmosphere will encourage the
production of high level ESD and a humid environment inhibits the charge to
a lesser level, presumably because it 'leaks' away. Then is it wrong for us
to attempt to 'dry' the local atmosphere in the hope of gaining consistent
ESD from an ESD gun, that is to say the more humid the environment the more
efficiently the discharge will transfer to the victim?

Incidentally, to add to the thread regarding intermediate level testing for
ESD and EFT. This exercise has revealed different failure mechanisms at
different ESD levels.

Your views would be appreciated.

Vic Gibling
Compliance Engineer
Marconi Applied Technologies

 

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RE: An ESD question

[Chris Maxwell]

Fred, et al

Vic's original question asked about test conditions; and that is what the 
responses dealt with.  As a matter of fact, the responses were very focused on 
the question that was asked.  

In the original question, I saw no discussion of the desired compliance level.  
 For all I know, Vic could be testing a bare chip or integrated circuit for 
which a compliance level of 1000V could be sufficient.The come-back which I 
 received, below,  assumes that Vic needs the 4KV, 8KV or higher compliance 
levels typical of most complete products.  That may be true; and I think that 
you bring up an important point that engineers need to focus on proper ESD 
design as well as ESD testing.

So, I consider your message to be worthwhile; even while I consider the 
criticism in its first sentence to be off target.  

Chris Maxwell | Design Engineer - Optical Division
email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024

NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA
web www.nettest.com | tel +1 315 797 4449 | 

 -Original Message-
 From: Fred Townsend [SMTP:f...@poasana.com]
 Sent: Wednesday, June 12, 2002 12:27 PM
 To:   Chris Maxwell
 Cc:   Gibling, Vic; emc-p...@majordomo.ieee.org
 Subject:  Re: An ESD question
 
 
 It is interesting to see how easy it is to lose focus.  The problem is not 
 the humidity, approach speed, etc. as Richard has suggested.  Yes, they are 
 factors but not the problem.  The problem is a massive design flaw. 800 volts 
 is way too low.  The fact there are multiple failure modes supports the 
 conclusion something major is wrong. The designers needs to review their ESD 
 suppression and grounding of this product. You may need to call in an ESD or 
 SI expert. This product is not ready for prime time.
 
 This discussion would be relevant if we were trying to sneak through a 
 product that passed at 4 KV but failed at 5 KV but not at 0.8KV.
 
 Fred Townsend
 

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Re: An ESD question

[bogdan matoga]

Vic:
The ambient relative humidity should have no impact on the performance of the
gut but only on the generation of  static charges. So, to improve the
performance in the field, I would suggest that you increase the R.H. at the
customer site(s) to about 50% which would eliminate the generation of
electrostatic charges and consequently the problems. This will give you time to
work on the equipment to minimize ESD susceptibility.
By the way, lower R.H. also occurs at low tamperatures.
Please let me know how things work out.
Bogdan.

Gibling, Vic wrote:

 Dear Group

 I tried to find David Pommerenke article's in the Journal of ESD on the Web
 but alas no downloadable version was found, so may I ask the group a
 question?

 We have an ESD field failure which is occurring in dry hot countries ( no
 surprise )which can be recreated with an ESD of -800V. In an attempt to get
 a high incidence of discharges we used a dehumidifier to create a dry
 environment. The result was a reduction in discharges.

 Thinking the problem through -now- as a dry atmosphere will encourage the
 production of high level ESD and a humid environment inhibits the charge to
 a lesser level, presumably because it 'leaks' away. Then is it wrong for us
 to attempt to 'dry' the local atmosphere in the hope of gaining consistent
 ESD from an ESD gun, that is to say the more humid the environment the more
 efficiently the discharge will transfer to the victim?

 Incidentally, to add to the thread regarding intermediate level testing for
 ESD and EFT. This exercise has revealed different failure mechanisms at
 different ESD levels.

 Your views would be appreciated.

 Vic Gibling
 Compliance Engineer
 Marconi Applied Technologies



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Re: An ESD question

[Fred Townsend]

It is interesting to see how easy it is to lose focus.  The problem is not the 
humidity, approach speed, etc. as Richard has suggested.  Yes, they are factors 
but not the problem.  The problem is a massive design flaw. 800 volts is way 
too low.  The fact there are multiple failure modes supports the conclusion 
something major is wrong. The designers needs to review their ESD suppression 
and grounding of this product. You may need to call in an ESD or SI expert. 
This product is not ready for prime time.

This discussion would be relevant if we were trying to sneak through a product 
that passed at 4 KV but failed at 5 KV but not at 0.8KV.

Fred Townsend

Chris Maxwell wrote:

 Vic,

 I agree, your product is probably seeing field failures because of the dry 
 conditions.  These dry conditions make the probability of an ESD event 
 higher.  This is due to the fact that, as personnel walk across carpets or 
 rub their clothing on chairs, there is no humidity in the air to help bleed 
 and equalize charge.  So, they have a higher probability of charging up and a 
 higher probability of discharging to your equipment.   (You probably already 
 know this.)

 Of course, your problems may not be due to people discharging to your 
 equipment.  It could be due to some other source of ESD.  It could be a 
 discharge from a nearby object.  However, the same argument holds.  The dry 
 atmosphere increases the probability.  (Hence the static cling present in 
 clothes that come out of a dryer.)

 So, in both cases, you are probably seeing more failures in a dry atmosphere 
 because the probability of an ESD event is higher.   Higher failure rates in 
 dry atmospheres are due to this probability increase.  The higher failure 
 rate is probably not due to a dry atmosphere ESD event being different from a 
 humid atmosphere ESD event.

 For testing, you are already generating the ESD event with a simulator.  The 
 ESD generator takes probability out of the equation.  You can generate a 
 discharge whenever you want.  So, in my humble opinion you don't need to 
 simulate the dry conditions.  I would simply follow IEC 1000-4-2, which 
 recommends test conditions with a humidity level between 30% and 60%.   With 
 this combination of ESD generator and humidity, you should get a discharge 
 whenever you want; and it should couple to the victim in proper fashion.

 I agree that you will see different performance at different levels.   I have 
 seen failures at 4KV air discharge that are not repeatable with 8KV air 
 discharge.   So it is worth the time to test at lower levels until you get up 
 to the compliance level that you are shooting for.

 Chris Maxwell | Design Engineer - Optical Division
 email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024

 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA
 web www.nettest.com | tel +1 315 797 4449 |

  -Original Message-
  From: Gibling, Vic [SMTP:vic.gibl...@marconi.com]
  Sent: Wednesday, June 12, 2002 3:26 AM
  To:   emc-p...@majordomo.ieee.org
  Subject:  An ESD question
 
 
 
  Dear Group
 
  I tried to find David Pommerenke article's in the Journal of ESD on the Web
  but alas no downloadable version was found, so may I ask the group a
  question?
 
  We have an ESD field failure which is occurring in dry hot countries ( no
  surprise )which can be recreated with an ESD of -800V. In an attempt to get
  a high incidence of discharges we used a dehumidifier to create a dry
  environment. The result was a reduction in discharges.
 
  Thinking the problem through -now- as a dry atmosphere will encourage the
  production of high level ESD and a humid environment inhibits the charge to
  a lesser level, presumably because it 'leaks' away. Then is it wrong for us
  to attempt to 'dry' the local atmosphere in the hope of gaining consistent
  ESD from an ESD gun, that is to say the more humid the environment the more
  efficiently the discharge will transfer to the victim?
 
  Incidentally, to add to the thread regarding intermediate level testing for
  ESD and EFT. This exercise has revealed different failure mechanisms at
  different ESD levels.
 
  Your views would be appreciated.
 
  Vic Gibling
  Compliance Engineer
  Marconi Applied Technologies
 
 
 
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Re: An ESD question

[Doug McKean]

As has been pointed out by Mr. Woods, humidity is only 
one of many parameters involved with ESD.  And simulating 
a dry environment in a chamber that's completely lined with 
metal surfaces might not be sufficient for simulating a dry 
customer environment. 

ESD failures at differing levels of voltage is an interesting 
problem since I've had at least two different types of 
failures each with entirely different casues.  

1. A unacceptable hard ESD failure at a level of say  'x KV' 
and any level higher is most likely a grounding problem. To 
lower level 'x KV', look at the grounding setup. 

2. A unacceptable hard ESD failure at a level of say  'x KV' 
but possibly no failure above this until a higher level is 
reached is more a decoupling problem in combination 
with a grounding problem. 

For instance, by a grounding problem I mean ground 
wire too short, improperly placed, ground wire too small, 
maybe braid should be used, maybe a strip of copper 
should be used, and if a braid or strip of copper are being 
used then maybe they're not wide enough, etc etc ... 

By a decoupling problem in combination with a grounding 
problem, I mean the ground problem described above 
in concert with incorrectly sized decoupling caps, the 
decoupling caps are improperly placed, leads too long 
on the caps, wrong sized ferrites if used, improperly 
placed ferrites, etc etc etc ... 

Regards, Doug McKean 



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RE: An ESD question

[Chris Maxwell]

Vic,

I agree, your product is probably seeing field failures because of the dry 
conditions.  These dry conditions make the probability of an ESD event higher.  
This is due to the fact that, as personnel walk across carpets or rub their 
clothing on chairs, there is no humidity in the air to help bleed and equalize 
charge.  So, they have a higher probability of charging up and a higher 
probability of discharging to your equipment.   (You probably already know 
this.)

Of course, your problems may not be due to people discharging to your 
equipment.  It could be due to some other source of ESD.  It could be a 
discharge from a nearby object.  However, the same argument holds.  The dry 
atmosphere increases the probability.  (Hence the static cling present in 
clothes that come out of a dryer.)

So, in both cases, you are probably seeing more failures in a dry atmosphere 
because the probability of an ESD event is higher.   Higher failure rates in 
dry atmospheres are due to this probability increase.  The higher failure rate 
is probably not due to a dry atmosphere ESD event being different from a humid 
atmosphere ESD event.  

For testing, you are already generating the ESD event with a simulator.  The 
ESD generator takes probability out of the equation.  You can generate a 
discharge whenever you want.  So, in my humble opinion you don't need to 
simulate the dry conditions.  I would simply follow IEC 1000-4-2, which 
recommends test conditions with a humidity level between 30% and 60%.   With 
this combination of ESD generator and humidity, you should get a discharge 
whenever you want; and it should couple to the victim in proper fashion.

I agree that you will see different performance at different levels.   I have 
seen failures at 4KV air discharge that are not repeatable with 8KV air 
discharge.   So it is worth the time to test at lower levels until you get up 
to the compliance level that you are shooting for.

Chris Maxwell | Design Engineer - Optical Division
email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024

NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA
web www.nettest.com | tel +1 315 797 4449 | 




 -Original Message-
 From: Gibling, Vic [SMTP:vic.gibl...@marconi.com]
 Sent: Wednesday, June 12, 2002 3:26 AM
 To:   emc-p...@majordomo.ieee.org
 Subject:  An ESD question
 
 
 
 Dear Group 
 
 I tried to find David Pommerenke article's in the Journal of ESD on the Web
 but alas no downloadable version was found, so may I ask the group a
 question?
 
 We have an ESD field failure which is occurring in dry hot countries ( no
 surprise )which can be recreated with an ESD of -800V. In an attempt to get
 a high incidence of discharges we used a dehumidifier to create a dry
 environment. The result was a reduction in discharges. 
 
 Thinking the problem through -now- as a dry atmosphere will encourage the
 production of high level ESD and a humid environment inhibits the charge to
 a lesser level, presumably because it 'leaks' away. Then is it wrong for us
 to attempt to 'dry' the local atmosphere in the hope of gaining consistent
 ESD from an ESD gun, that is to say the more humid the environment the more
 efficiently the discharge will transfer to the victim?
 
 Incidentally, to add to the thread regarding intermediate level testing for
 ESD and EFT. This exercise has revealed different failure mechanisms at
 different ESD levels.
 
 Your views would be appreciated.
 
 Vic Gibling
 Compliance Engineer
 Marconi Applied Technologies
 
  
 
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RE: An ESD question

[richwoods]

Humidity is not the only variable, and may not be your major variable.
Repeatability of ESD results is a statistical problem. Consider the
variables:
-humidity
-approach speed (for non-contact discharge)
-angle of the probe (for non-contact discharge)
-synchronization of the ESD application with the various logic states of the
EUT
-rise time and peak di/dt variance as applied ESD voltage is changed
-variance between ESD guns

And I am sure there are more variables. The only way one can really
determine a product's real ESD immunity is to apply thousands of hits at
different voltage levels and apply a statistical evaluation. In the end, one
can only say that the equipment is immune to X volts with Y confidence.

Good luck,

Richard Woods
Sensormatic Electronics
Tyco International


-Original Message-
From: Gibling, Vic [mailto:vic.gibl...@marconi.com]
Sent: Wednesday, June 12, 2002 3:26 AM
To: emc-p...@majordomo.ieee.org
Subject: An ESD question




Dear Group 

I tried to find David Pommerenke article's in the Journal of ESD on the Web
but alas no downloadable version was found, so may I ask the group a
question?

We have an ESD field failure which is occurring in dry hot countries ( no
surprise )which can be recreated with an ESD of -800V. In an attempt to get
a high incidence of discharges we used a dehumidifier to create a dry
environment. The result was a reduction in discharges. 

Thinking the problem through -now- as a dry atmosphere will encourage the
production of high level ESD and a humid environment inhibits the charge to
a lesser level, presumably because it 'leaks' away. Then is it wrong for us
to attempt to 'dry' the local atmosphere in the hope of gaining consistent
ESD from an ESD gun, that is to say the more humid the environment the more
efficiently the discharge will transfer to the victim?

Incidentally, to add to the thread regarding intermediate level testing for
ESD and EFT. This exercise has revealed different failure mechanisms at
different ESD levels.

Your views would be appreciated.

Vic Gibling
Compliance Engineer
Marconi Applied Technologies

 

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An ESD question

[Gibling, Vic]

Dear Group 

I tried to find David Pommerenke article's in the Journal of ESD on the Web
but alas no downloadable version was found, so may I ask the group a
question?

We have an ESD field failure which is occurring in dry hot countries ( no
surprise )which can be recreated with an ESD of -800V. In an attempt to get
a high incidence of discharges we used a dehumidifier to create a dry
environment. The result was a reduction in discharges. 

Thinking the problem through -now- as a dry atmosphere will encourage the
production of high level ESD and a humid environment inhibits the charge to
a lesser level, presumably because it 'leaks' away. Then is it wrong for us
to attempt to 'dry' the local atmosphere in the hope of gaining consistent
ESD from an ESD gun, that is to say the more humid the environment the more
efficiently the discharge will transfer to the victim?

Incidentally, to add to the thread regarding intermediate level testing for
ESD and EFT. This exercise has revealed different failure mechanisms at
different ESD levels.

Your views would be appreciated.

Vic Gibling
Compliance Engineer
Marconi Applied Technologies

 

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[Fwd: RE: ESD Question]

[David Heald]

Forwarded for Mike Hopkins.

 Original Message 
Subject: RE: ESD Question
List-Post: emc-pstc@listserv.ieee.org
Date: Wed, 30 May 2001 16:06:48 -0400
From: Mike  Hopkins mhopk...@thermokeytek.com
To: 'Chris Maxwell' chris.maxw...@nettest.com,'Sandy
Mazzola'mazzo...@symbol.com, emc-p...@majordomo.ieee.org

There is an amendment to IEC 61000-4-2 in process that is intended to
clarify the issue of connector pins. I basically states that for
connectors
with metal shells, a contact mode discharge is performed to the shell.
For
plastic connectors, an air discharge is done in the vicinity of the
connector -- if a break-down to a pin occurs in either case, tough luck.
There was never any intention that discharges be done to individual pins
in
a connector.

Some other specific exclusions include ESD sensitive connectors -- scope
inputs, etc... that are marked as ESD sensitive and there is reference
to
that in the product documentation. Also excluded are battery contacts
which
might be contacted when the batteries are changed but are not accessed
during operation of the product.

Hope this is helpful..

Best Regards,

Mike Hopkins
KeyTek
(member IEC SC77B WG9, which is the working group responsible for IEC
61000-4-2)

-Original Message-
From: Chris Maxwell [mailto:chris.maxw...@nettest.com]
Sent: Wednesday, May 30, 2001 2:07 PM
To: 'Sandy Mazzola'; emc-p...@majordomo.ieee.org
Subject: RE: ESD Question



Hi Sandy,

Have you seen the sunshine in your end of New York?  If you have, send
it
back!!

Personally, I have never seen a product that required air or contact ESD
testing on the individual pins of connectors.  I can only speak for
products
tested to EN 50082-1(Generic Immunity), EN 50082-1(Generic
Immunity/Heavy
Industrial), ETS 300-386-1(Telcom EMC) and EN 61326-1 (Test ,
Measurement
and Control Equipment EMC).

The basic standard which covers ESD testing itself (for the product and
product family standards mentioned above) is EN 61000-4-2.  EN 61000-4-2
is
also the basic standard which EN 55024 references for ESD testing.   EN
61000-4-2 gives no definite example or statement regarding discharge to
individual connector pins.  It just says to discharge to all locations
normally accessible by the customer (paraphrased).  So, this can be
rationalized either way.Apparantly, the authors of EN 55024 have
already
done the rationalization for you.  

What I have typically seen  and performed is ESD testing whereby direct
contact discharges are made to the shells of connectors (i.e. D-subs
)
but not to the individual pins.

Since EN 61000-4-2 gives no exact direction, I think that there has been
a
general consensus of interpretation (my own words) that ESD is not
required on individual pins.  I have heard some myth/horror stories that
say
otherwise from people selling ESD hardened connectors, IC's  but
they
turned out to be exaggerations.   

Having said that, I must add the caveat that there may be standards and
products that are an exception, especially in the military, aerospace or
medical fields.  I just haven't seen any. 

!PLEASE NOTE THE NEW EMAIL ADDRESS
Chris Maxwell
Design Engineer
NetTest
6 Rhoads Drive, Building 4
Utica,NY 13502
email: chris.maxw...@nettest.com
phone:  315-266-5128
fax: 315-797-8024
  

 -Original Message-
 From: Sandy Mazzola [SMTP:mazzo...@symbol.com]
 Sent: Wednesday, May 30, 2001 9:30 AM
 To:   emc-p...@majordomo.ieee.org
 Subject:  ESD Question
 
 Hi all,
   
In EN 55024: 1998  Page 9 Paragraph 4.2.1,  I found the following
 statement:  The  application of electrostatic discharges to the contacts
 of open connectors is not required by this publication
 
  My question is  twofold has everybody interpreted this to mean that
 no air discharges or contact discharges are required to the connector or
 pins of the open connector.
 And secondly  if the answer to the above is no discharges  of any type are
 required, what other publications would require  either air or contact
 discharges to open connectors.
 
 Thanks
 
 Sandy Mazzola  
 
 Santo Mazzola
 Regulatory Engineer
 Symbol Technologies Inc
 1 Symbol Plaza
 Holtsville, N. Y. 11742-1300
 Phone:  (631) 738-5373
 Fax:  (631) 738-3318
 E-mail: mazzo...@symbol.com
 
   File: Sandy Mazzola.vcf  

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Re: ESD Question

[John Woodgate]

sb14bd8c@symbol.com, Sandy Mazzola mazzo...@symbol.com
inimitably wrote:
 In EN 55024: 1998  Page 9 Paragraph 4.2.1,  I found the following statement:  
The  application of electrostatic discharges to the contacts of open 
connectors 
is not required by this publication

 My question is  twofold has everybody interpreted this to mean that no 
 air 
discharges or contact discharges are required to the connector or  pins of the 
open connector.
And secondly  if the answer to the above is no discharges  of any type are 
required, what other publications would require  either air or contact 
discharges to open connectors.

The point that is being made in EN55024 is that some people interpreted
the Basic Standard, IEC61000-4-2, as requiring the contacts of
connectors to be zapped, which is pretty unlikely in practice and almost
impossible to cope with in many cases.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. Phone +44 (0)1268 747839
Fax +44 (0)1268 777124. http://www.jmwa.demon.co.uk Why not call a vertically-
applied manulo-pedally-operated quasi-planar chernozem-penetrating and 
excavating implement a SPADE?

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