Re: [PSES] EU's new approach directive transitions

2016-03-31 Thread ce-test, qualified testing bv - Gert Gremmen 
A "risk management process" describes how a company management addresses risks 
with their products.
It describes responsibilities and functions and the process of risks, hazards 
and incidents.
The "risk assessment" describes the process of determining risk of a device.
Techniques for risk assessment are Top-down and bottom-up analysis and FMEA . 

Some facts I learned:

1. No risk assessment process will tell you what risks are acceptable or not.
2. The risk assessment will document all risks/aspects you have considered, and 
if carried out
probably allows you to conclude that you did not overlook something: the most 
important conclusion.
3. Techniques as FMEA allow you to rank risks in order of relevance, so as to 
cope with highest risks first.
3b. The order is created by multiplying chance , severity and detectability 
into a arbitrary risk value.
3c. There are not much conventions in valuing those 3 factors and applying 
numeric values to them. Each analysis is engineer specific.
Only the ranking is an objective result. 
4. This ranking allows the risk management engineer to define a arbitrary risk 
threshold value above what any risk needs to be fixed.
5. The result of the full process is a "remaining risks list" that can be 
addressed in educating your customers. (don't dry the cat in the microwave)

If you take a machine directive standard such as the 60204 you can clearly see 
how risk enabled standards interact with the risk management process.


Regards,

Ing. Gert Gremmen
Approvals manager



+ ce marking of electrical/electronic equipment
+ Independent Consultancy Services
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From: Nick Williams [mailto:nick.willi...@conformance.co.uk] 
Sent: Friday 1 April 2016 00:03
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] EU's new approach directive transitions

David,

The risk assessment you refer to below is not same as the risk assessment 
referred to in the new LVD (and some other NLF directives). The risk assessment 
below is specifically aimed at determining whether or not the product presents 
a risk which is sufficient to warrant post market action, and in particular 
whether or not a product recall is necessary. This is obviously related to the 
product design risk assessment which is required before placing the product on 
the market, but it is not the same thing.

Nick. 




On 31 Mar 2016, at 22:09, David K Bell  wrote:

Scott,
With regard to the risk assessment requirement in the Directives revised under 
the New Legislative Framework (NLF):
This excerpt is from a discussion of the proposed EU Consumer Product Safety 
Regulation (CPSR):
 
The European Commission will undertake a risk analysis of the product to 
determine whether the product is likely to pose a 'serious' risk. The default 
risk analysis methodology to be used is the already established EU Risk 
Assessment Methodology (Decision 2010/15/EU), by which products can be assessed 
and classified as posing a 'Low', 'Medium', 'High' or 'Serious' risk. If this 
risk assessment methodology is not appropriate for the particular product, the 
Commission must give a detailed description of the methodology used in its 
place. 
 
Appendix 5 of Decision 2010/15/EU on pages 33—64 covers Risk Assessment.  This 
is the methodology that a EU enforcement body would use to determine if a 
product poses a serious risk and should therefore be withdrawn from the market 
and notified to other EU member states via the EU RAPEX rapid alert system.  
Any risk analysis that we do to satisfy the requirements of the new LV  and EMC 
Directives should be no less rigorous.

Best regards,

David K. Bell
Senior Regulatory Compliance Engineer
Milestone AV Technologies 
david.b...@milestone.com
+1.952.225.6782


On Thu, Mar 31, 2016 at 11:35 AM, Scott Xe  wrote:
There are two major changes in new LVD.  One is the risk assessm

Re: [PSES] EU's new approach directive transitions

2016-03-31 Thread Nick Williams 
David,

The risk assessment you refer to below is not same as the risk assessment 
referred to in the new LVD (and some other NLF directives). The risk assessment 
below is specifically aimed at determining whether or not the product presents 
a risk which is sufficient to warrant post market action, and in particular 
whether or not a product recall is necessary. This is obviously related to the 
product design risk assessment which is required before placing the product on 
the market, but it is not the same thing.

Nick. 




> On 31 Mar 2016, at 22:09, David K Bell  wrote:
> 
> Scott,
> 
> With regard to the risk assessment requirement in the Directives revised 
> under the New Legislative Framework (NLF):
> 
> This excerpt is from a discussion of the proposed EU Consumer Product Safety 
> Regulation (CPSR):
> 
>  
> The European Commission will undertake a risk analysis of the product to 
> determine whether the product is likely to pose a 'serious' risk. The default 
> risk analysis methodology to be used is the already established EU Risk 
> Assessment Methodology (Decision 2010/15/EU), by which products can be 
> assessed and classified as posing a 'Low', 'Medium', 'High' or 'Serious' 
> risk. If this risk assessment methodology is not appropriate for the 
> particular product, the Commission must give a detailed description of the 
> methodology used in its place.
>  
> Appendix 5 of Decision 2010/15/EU on pages 33—64 covers Risk Assessment.  
> This is the methodology that a EU enforcement body would use to determine if 
> a product poses a serious risk and should therefore be withdrawn from the 
> market and notified to other EU member states via the EU RAPEX rapid alert 
> system.  Any risk analysis that we do to satisfy the requirements of the new 
> LV  and EMC Directives should be no less rigorous.
> 
> Best regards,
> 
> David K. Bell
> Senior Regulatory Compliance Engineer
> Milestone AV Technologies
> 
> david.b...@milestone.com 
> +1.952.225.6782
> 
> 
> 
> On Thu, Mar 31, 2016 at 11:35 AM, Scott Xe  > wrote:
> There are two major changes in new LVD.  One is the risk assessment that is 
> to be the obligation for the manufacturers.  The other one is that the DoC is 
> required to have object of declaration.
> 
> The risk assessment is unclear how to do it and any reference to follow.  
> Currently there is few testing laboratories to provide such service to the 
> manufacturers.  Hope there is harmonised standard and/or guidance for 
> compliance in near future.
> 
> Scott
> 
> 
>> On 31 Mar, 2016, at 1:50 am, Ronald Pickard 
>> > > wrote:
>> 
>> Hi Charlie,
>> Thank you for your reply along with those linked references. Those ETSI 
>> links provide projected target dates for approval and availability for the 
>> new/revised standards being drafted for the RED, which are generally 
>> targeted to be complete by the 13-Jun-2017 effectivity date for the RED. 
>> Kudos to ETSI for that work.
>>  
>> Best regards,
>>  
>> Ron Pickard
>> Regulatory Compliance Engineer
>> Compound Photonics 
>> D | +1 (602) 883-8039 
>>  
>> From: Charlie Blackham [mailto:char...@sulisconsultants.com 
>> ] 
>> Sent: Tuesday, March 29, 2016 11:34 PM
>> To: Ronald Pickard > >; EMC-PSTC@LISTSERV.IEEE.ORG 
>> 
>> Subject: RE: EU's new approach directive transitions
>>  
>> Ron
>>  
>> Few short answers:
>>  
>> · No sign of that happening at all and I cannot see it happening
>> · No, existing Directives are repealed by the new Directives on the 
>> dates indicated,  but you may wish to look at Recommended format for DoC 
>> that can reference existing and new 
>> Directives,http://ec.europa.eu/DocsRoom/documents/14886/attachments/1/translations/en/renditions/native
>>  
>> 
>>   (referenced from 
>> http://ec.europa.eu/growth/sectors/electrical-engineering/emc-directive/index_en.htm
>>  
>> 
>>  )
>> · ETSI are working hard on updating over 150 standards, some more 
>> information available:
>> o   https://docbox.etsi.org/Workshop/2015/201511_RED-WORKSHOP/ 
>>  for 
>> presentations from November workshop
>> o   Work program on radio standards: 
>> http://webapp.etsi.org/ena/cvp.asp?search=RADIO 
>>  and a number of RED 
>> standards have a been published or are available as final draft
>> o   Work program on EMC standards: 
>> http://webapp.etsi.org/ena/cvp.asp?Search=emc&Status=&Directive=&submit1=Get+Work+Items
>>  
>>

Re: [PSES] EU's new approach directive transitions

2016-03-31 Thread Nick Williams 
EN ISO 12100 is good and useful but EN ISO 14971 "Medical devices — Application 
of risk management to medical devices” is actually more relevant to some 
consumer type products 

Nick. 



> On 31 Mar 2016, at 20:32, Nyffenegger, Dave  
> wrote:
> 
> Risk assessments are not new and it’s a requirement of the current Machinery 
> Directive from 2006 and probably for some time before.  A principle HS for 
> the MD is EN ISO 12100:2010.  Many of the basic concepts can be applied to 
> non-machinery. I’d think that standard or one similar would become an HS for 
> the LVD.
>  


-

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Re: [PSES] Commom mode current vs. differential mode current and LISN

2016-03-31 Thread Cortland Richmond 

On 3/31/2016 4:47 PM, Grasso, Charles wrote:

Why are you looking at the "noise" in the time domain?
What spec are you trying to comply with?


It was already non-compliant and I had to find out how to fix it.

I do this kind of probing to find out where [stuff] comes from and where 
it goes, in THIS case, where the highest E and H field FS was **on the 
PWB**.  A "nude" 'scope probe with suitable insulation slipped over it 
works for close-in E-field, and miniature coax with a loop on the end (~ 
2mm diameter) for sniffing the H field -- plus one can rotate it to find 
traces carrying switching noise around on the board; it long ago ceased 
to surprise me to find the relevant bypass capacitors some distance away 
from the SMPS


That's AFTER the first items are sent to a test lab and fail, usually.  
When I was at Alcatel USA (formerly DSC) I asked for got read-only 
privileges on all schematics and PWB's in the CAD shop when I was hired, 
and could stop that [rude word] before it got built. Heh.



Cortland Richmond

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Re: [PSES] EU's new approach directive transitions

2016-03-31 Thread David K Bell 
Scott,

With regard to the risk assessment requirement in the Directives revised
under the New Legislative Framework (NLF):

This excerpt is from a discussion of the proposed EU Consumer Product
Safety Regulation (CPSR):



The European Commission will undertake a risk analysis of the product to
determine whether the product is likely to pose a 'serious' risk. The
default risk analysis methodology to be used is the already established EU
Risk Assessment Methodology (Decision 2010/15/EU), by which products can be
assessed and classified as posing a 'Low', 'Medium', 'High' or 'Serious'
risk. If this risk assessment methodology is not appropriate for the
particular product, the Commission must give a detailed description of the
methodology used in its place.



Appendix 5 of Decision 2010/15/EU on pages 33—64 covers Risk Assessment.
This is the methodology that a EU enforcement body would use to determine
if a product poses a serious risk and should therefore be withdrawn from
the market and notified to other EU member states via the EU RAPEX rapid
alert system.  Any risk analysis that we do to satisfy the requirements of
the new LV  and EMC Directives should be no less rigorous.


Best regards,


*David K. Bell*
Senior Regulatory Compliance Engineer
Milestone AV Technologies

david.b...@milestone.com

+1.952.225.6782


On Thu, Mar 31, 2016 at 11:35 AM, Scott Xe  wrote:

> There are two major changes in new LVD.  One is the risk assessment that
> is to be the obligation for the manufacturers.  The other one is that the
> DoC is required to have object of declaration.
>
> The risk assessment is unclear how to do it and any reference to follow.
> Currently there is few testing laboratories to provide such service to the
> manufacturers.  Hope there is harmonised standard and/or guidance for
> compliance in near future.
>
> Scott
>
>
> On 31 Mar, 2016, at 1:50 am, Ronald Pickard <
> ronald.pick...@compoundphotonics.com> wrote:
>
> Hi Charlie,
> Thank you for your reply along with those linked references. Those ETSI
> links provide projected target dates for approval and availability for the
> new/revised standards being drafted for the RED, which are generally
> targeted to be complete by the 13-Jun-2017 effectivity date for the RED.
> Kudos to ETSI for that work.
>
> Best regards,
>
> *Ron Pickard*
> Regulatory Compliance Engineer
> *Compound Photonics*
> D | +1 (602) 883-8039
>
> *From:* Charlie Blackham [mailto:char...@sulisconsultants.com
> ]
> *Sent:* Tuesday, March 29, 2016 11:34 PM
> *To:* Ronald Pickard ;
> EMC-PSTC@LISTSERV.IEEE.ORG
> *Subject:* RE: EU's new approach directive transitions
>
> Ron
>
> Few short answers:
>
> · No sign of that happening at all and I cannot see it happening
> · No, existing Directives are repealed by the new Directives on
> the dates indicated,  but you may wish to look at Recommended format for
> DoC that can reference existing and new Directives,
> http://ec.europa.eu/DocsRoom/documents/14886/attachments/1/translations/en/renditions/native
> (referenced from
> http://ec.europa.eu/growth/sectors/electrical-engineering/emc-directive/index_en.htm
>  )
> · ETSI are working hard on updating over 150 standards, some more
> information available:
> o   https://docbox.etsi.org/Workshop/2015/201511_RED-WORKSHOP/ for
> presentations from November workshop
> o   Work program on radio standards:
> http://webapp.etsi.org/ena/cvp.asp?search=RADIO and a number of RED
> standards have a been published or are available as final draft
> o   Work program on EMC standards:
> http://webapp.etsi.org/ena/cvp.asp?Search=emc&Status=&Directive=&submit1=Get+Work+Items
> · Lists of HS for current standards can be used for new
> Directives until new lists are published as per relevant article in the
> directive such as article 27 of the 2014/35/EU LVD.
> · So far I’m aware of:
> o   LVD guidance on transition to new LVD,
> http://ec.europa.eu/DocsRoom/documents/13141/attachments/1/translations/en/renditions/native
>  available at
> http://ec.europa.eu/growth/sectors/electrical-engineering/lvd-directive/index_en.htm
> o   RED guidance is being worked on, but RED is not mandatory until 2017
> so there is more time for this.
> http://ec.europa.eu/DocsRoom/documents/11983/attachments/1/translations/en/renditions/pdf
>  provides guidance on transitions for equipment moving into and out of
> R&TTE/RED.
> · No one is expecting anything.
>
> Regards
> Charlie
>
> *Charlie Blackham*
> *Sulis Consultants Ltd*
> *Tel: +44 (0)7946 624317 <%2B44%20%280%297946%20624317>*
> *LinkedIn: **uk.linkedin.com/in/charlieblackham/*
> 
> *Web: www.sulisconsultants.com *
> Registered in England and Wales, number 05466247
>
>
>
> *From:* Ronald Pickard [mailto:ronald.pick...@compoundphotonics.com
> ]
> *Sent:* 29 March 2016 23:46
> *To:* EMC-PSTC@LISTSERV.IEEE.ORG
> *Subject:* [PSES] EU's new approach d

Re: [PSES] EU's new approach directive transitions

2016-03-31 Thread John Allen 
Rich

 

Life is a risk!

 

Nothing in life is a certainty, unless you include death which is a certainly – 
but then when, how, why?

 

“Risk assessment” has actually been part of safety for decades if not centuries 
or millennia, even if it was not formally understood to be, and there are very 
many quotable examples such as the decisions that a government in an 
international relations crisis /military commander  during a battle/parents 
deciding which school  to send their kid to, has to make  is a risk assessment.

 

Therefore, if done reasonably properly, sensibly and “formally”, it can be 
applied to “safety, and is widely thus used already. 

 

Used it many times myself in both military and civilian situations, including 
LVD compliance and so on  - and it is specially required  by the Machinery 
Directive for compliance with that. FWIW, in IEC/EN 601010-1 Clause 17 it is 
given as a rational way of demonstrating compliance with the standard if there 
is something  specific in it with which you cannot comply but you believe that 
you can still demonstrate by other means/evidence that you meet its overall 
requirements.

 

BTW, before I had to “confront” the concept of risk assessment in the 1990s 
when I got a job in the defence industry, I did not understand the whole 
concept – and it took quite some time before I became reasonably “comfortable” 
with it . And, one of the major issues to address and try to understand is the 
concept of the “equation” that is the “harm”/” how bad” V “probabily”/”how 
often “  the “incident(s)” are considered to occur.

 

John Allen

W.London, UK

 

Therefore, provided that the p

 

From: Richard Nute [mailto:ri...@ieee.org] 
Sent: 31 March 2016 21:18
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] EU's new approach directive transitions

 

 

 

Scott Xe said, “The risk assessment is unclear how to do it and any reference 
to follow.”

 

I agree.  Risk assessment is an abstraction.  ISO/IEC Guide 51, the basis for 
risk assessment, defines risk as the “combination of the probability of 
occurrence of harm and the severity of that harm.”  Other sources define “risk” 
as a probability of an unwanted occurrence, not a combination with something 
else.

 

Guide 51 defines risk assessment as “procedure based on the risk analysis to 
determine whether the tolerable risk has been achieved.”  

 

Then, risk analysis is “systematic use of available information to identify 
hazards and to estimate the risk.”

 

And, tolerable risk is “risk which is accepted in a given context based on the 
current values of society.”

 

Good luck in applying risk assessment to determine the safety of products!

 

 

Rich

 

 

 

-


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Re: [PSES] Commom mode current vs. differential mode current and LISN

2016-03-31 Thread Grasso, Charles 
Hello - Why are you looking at the "noise" in the time domain?
What spec are you trying to comply with?

My assumption is that (if there is a LISN) there will be a spec in 
the frequency domain - am I wrong?

Best Regards
Charles Grasso
Compliance Engineer
Echostar Communications
(w) 303-706-5467
(c) 303-204-2974
(t) 3032042...@vtext.com
(e) charles.gra...@echostar.com
(e2) chasgra...@gmail.com

-Original Message-
From: Cortland Richmond [mailto:k...@earthlink.net] 
Sent: Thursday, March 31, 2016 12:49 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Commom mode current vs. differential mode current and LISN

On 3/29/2016 5:59 PM, Elliott Martinson wrote:
> But noise is chaotic, and subsequent measurements of the L conductor 
> only won’t even be exactly the same. The phase relationships of 
> different noise signals from different sources in the device are 
> constantly changing depending on when the measurement was made as well.

It's not "noise," though, in the classical sense -- and it can be distinguished 
by frequency and (in the time domain) by waveform. For one examples see my 
photo at 
https://www.flickr.com/photos/101461001@N06/25883518240/in/dateposted-public/
f


I had been called out of retirement on contract, and brought in my own o'scope, 
since the lab's equipment was all in use. The ringing waveform was the signal 
from a LISN (into 50 Ohms) and the waveform below it was taken with a suitably 
insulated scope probe near the SMPS causing the problem.

Cortland Richmond

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Re: [PSES] EU's new approach directive transitions

2016-03-31 Thread Richard Nute 
 

 

Scott Xe said, “The risk assessment is unclear how to do it and any reference 
to follow.”

 

I agree.  Risk assessment is an abstraction.  ISO/IEC Guide 51, the basis for 
risk assessment, defines risk as the “combination of the probability of 
occurrence of harm and the severity of that harm.”  Other sources define “risk” 
as a probability of an unwanted occurrence, not a combination with something 
else.

 

Guide 51 defines risk assessment as “procedure based on the risk analysis to 
determine whether the tolerable risk has been achieved.”  

 

Then, risk analysis is “systematic use of available information to identify 
hazards and to estimate the risk.”

 

And, tolerable risk is “risk which is accepted in a given context based on the 
current values of society.”

 

Good luck in applying risk assessment to determine the safety of products!

 

 

Rich

 

 

 


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Re: [PSES] EU's new approach directive transitions

2016-03-31 Thread Nyffenegger, Dave 
Risk assessments are not new and it’s a requirement of the current Machinery 
Directive from 2006 and probably for some time before.  A principle HS for the 
MD is EN ISO 12100:2010.  Many of the basic concepts can be applied to 
non-machinery. I’d think that standard or one similar would become an HS for 
the LVD.

In my experience the test labs that do certification work do not do risk 
assessment, it is a responsibility of the manufacturer.  They will however 
review your risk assessment when certifying to other standards.  The test labs 
I have worked with typically are set up with three independent internal 
divisions, one that does certifications to standards, one that does factory 
inspections (OSHA NRTLs), and one that will do design consulting services.  As 
was explained to me, these divisions are intentionally separated and do not 
work with each other as to maintain their independent functions and avoid 
conflict of interest.  I imagine the design consulting services division of 
some test labs would offer risk assessment/reduction services, I have known 
other companies that have contracted that out.

-Dave

From: Scott Xe [mailto:scott...@gmail.com]
Sent: Thursday, March 31, 2016 12:36 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] EU's new approach directive transitions

There are two major changes in new LVD.  One is the risk assessment that is to 
be the obligation for the manufacturers.  The other one is that the DoC is 
required to have object of declaration.

The risk assessment is unclear how to do it and any reference to follow.  
Currently there is few testing laboratories to provide such service to the 
manufacturers.  Hope there is harmonised standard and/or guidance for 
compliance in near future.

Scott


On 31 Mar, 2016, at 1:50 am, Ronald Pickard 
mailto:ronald.pick...@compoundphotonics.com>>
 wrote:

Hi Charlie,
Thank you for your reply along with those linked references. Those ETSI links 
provide projected target dates for approval and availability for the 
new/revised standards being drafted for the RED, which are generally targeted 
to be complete by the 13-Jun-2017 effectivity date for the RED. Kudos to ETSI 
for that work.

Best regards,

Ron Pickard
Regulatory Compliance Engineer
Compound Photonics
D | +1 (602) 883-8039

From: Charlie Blackham [mailto:char...@sulisconsultants.com]
Sent: Tuesday, March 29, 2016 11:34 PM
To: Ronald Pickard 
mailto:ronald.pick...@compoundphotonics.com>>;
 EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: EU's new approach directive transitions

Ron

Few short answers:

• No sign of that happening at all and I cannot see it happening
• No, existing Directives are repealed by the new Directives on the 
dates indicated,  but you may wish to look at Recommended format for DoC that 
can reference existing and new 
Directives,http://ec.europa.eu/DocsRoom/documents/14886/attachments/1/translations/en/renditions/native
  (referenced from 
http://ec.europa.eu/growth/sectors/electrical-engineering/emc-directive/index_en.htm
 )
• ETSI are working hard on updating over 150 standards, some more 
information available:
o   https://docbox.etsi.org/Workshop/2015/201511_RED-WORKSHOP/ for 
presentations from November workshop
o   Work program on radio standards: 
http://webapp.etsi.org/ena/cvp.asp?search=RADIO and a number of RED standards 
have a been published or are available as final draft
o   Work program on EMC standards: 
http://webapp.etsi.org/ena/cvp.asp?Search=emc&Status=&Directive=&submit1=Get+Work+Items
• Lists of HS for current standards can be used for new Directives 
until new lists are published as per relevant article in the directive such as 
article 27 of the 2014/35/EU LVD.
• So far I’m aware of:
o   LVD guidance on transition to new 
LVD,http://ec.europa.eu/DocsRoom/documents/13141/attachments/1/translations/en/renditions/native
 available 
athttp://ec.europa.eu/growth/sectors/electrical-engineering/lvd-directive/index_en.htm
o   RED guidance is being worked on, but RED is not mandatory until 2017 so 
there is more time for this.  
http://ec.europa.eu/DocsRoom/documents/11983/attachments/1/translations/en/renditions/pdf
 provides guidance on transitions for equipment moving into and out of 
R&TTE/RED.
• No one is expecting anything.

Regards
Charlie

Charlie Blackham
Sulis Consultants Ltd
Tel: +44 (0)7946 624317
LinkedIn: 
uk.linkedin.com/in/charlieblackham/
Web: www.sulisconsultants.com
Registered in England and Wales, number 05466247



From: Ronald Pickard [mailto:ronald.pick...@compoundphotonics.com]
Sent: 29 March 2016 23:46
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] EU's new approach directive transitions

Hi to all, and especially to those that are knowledgeable of the EU’s processes 
on this subject,

I know that this subject has been d

Re: [PSES] Commom mode current vs. differential mode current and LISN

2016-03-31 Thread Ken Javor 
I didn't see the post to which Cortland is responding, but if I had I would
have said that power supply noise is of two types, narrowband and broadband.
The narrowband fundamental and harmonics from the switched mode power supply
(SMPS) are (generally*) fixed in frequency and amplitude, and are quite
repeatable unless the load on the secondary side of that power supply is
changing drastically.  If the SMPS operates off a dc bus, that is all the
noise there is.  If it operates off an ac bus, then there are rectification
harmonics, which are broadband and "chaotic" in the sense that they are not
at fixed frequencies, but the envelope will be well-defined and they are
differential mode, so the filter design for that is straightforward.

I can always tell a commercial design that has been adapted for military use
by the telltale conducted emission signature which is well-behaved above the
commercial limit start frequency of 150 kHz but balloons up at the lower
frequencies required by the mil limit which starts at 10 kHz, so we see the
unfiltered rectification harmonics decreasing in amplitude as they approach
150 kHz.

* Some power supply designs (Vicor is one) change switching frequency as
load changes instead of duty cycle, so if the load is changing the switching
frequency changes with it. Designing a filter for a power supply like that
would have to involve filtering for both light and heavy loads. I have no
direct experience with such designs.

Ken Javor
Phone: (256) 650-5261


> From: Cortland Richmond 
> Reply-To: 
> Date: Thu, 31 Mar 2016 14:48:48 -0400
> To: 
> Subject: Re: [PSES] Commom mode current vs. differential mode current and LISN
> 
> On 3/29/2016 5:59 PM, Elliott Martinson wrote:
>> But noise is chaotic, and subsequent measurements of the L conductor
>> only won¹t even be exactly the same. The phase relationships of
>> different noise signals from different sources in the device are
>> constantly changing depending on when the measurement was made as well.
> 
> It's not "noise," though, in the classical sense -- and it can be
> distinguished by frequency and (in the time domain) by waveform. For one
> examples see my photo at
> https://www.flickr.com/photos/101461001@N06/25883518240/in/dateposted-public/
> f
> 
> 
> I had been called out of retirement on contract, and brought in my own
> o'scope, since the lab's equipment was all in use. The ringing waveform
> was the signal from a LISN (into 50 Ohms) and the waveform below it was
> taken with a suitably insulated scope probe near the SMPS causing the
> problem.
> 
> Cortland Richmond
> 
> -
> 
> 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)
> 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 


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:

Re: [PSES] Commom mode current vs. differential mode current and LISN

2016-03-31 Thread Cortland Richmond 

On 3/29/2016 5:59 PM, Elliott Martinson wrote:
But noise is chaotic, and subsequent measurements of the L conductor 
only won’t even be exactly the same. The phase relationships of 
different noise signals from different sources in the device are 
constantly changing depending on when the measurement was made as well. 


It's not "noise," though, in the classical sense -- and it can be 
distinguished by frequency and (in the time domain) by waveform. For one 
examples see my photo at
https://www.flickr.com/photos/101461001@N06/25883518240/in/dateposted-public/ 
f



I had been called out of retirement on contract, and brought in my own 
o'scope, since the lab's equipment was all in use. The ringing waveform 
was the signal from a LISN (into 50 Ohms) and the waveform below it was 
taken with a suitably insulated scope probe near the SMPS causing the 
problem.


Cortland Richmond

-

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)
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:

Re: [PSES] EU's new approach directive transitions

2016-03-31 Thread Scott Xe 
There are two major changes in new LVD.  One is the risk assessment that is to 
be the obligation for the manufacturers.  The other one is that the DoC is 
required to have object of declaration.

The risk assessment is unclear how to do it and any reference to follow.  
Currently there is few testing laboratories to provide such service to the 
manufacturers.  Hope there is harmonised standard and/or guidance for 
compliance in near future.

Scott


> On 31 Mar, 2016, at 1:50 am, Ronald Pickard 
>  > wrote:
> 
> Hi Charlie,
> Thank you for your reply along with those linked references. Those ETSI links 
> provide projected target dates for approval and availability for the 
> new/revised standards being drafted for the RED, which are generally targeted 
> to be complete by the 13-Jun-2017 effectivity date for the RED. Kudos to ETSI 
> for that work.
>  
> Best regards,
>  
> Ron Pickard
> Regulatory Compliance Engineer
> Compound Photonics 
> D | +1 (602) 883-8039
>  
> From: Charlie Blackham [mailto:char...@sulisconsultants.com 
> ] 
> Sent: Tuesday, March 29, 2016 11:34 PM
> To: Ronald Pickard  >; EMC-PSTC@LISTSERV.IEEE.ORG 
> 
> Subject: RE: EU's new approach directive transitions
>  
> Ron
>  
> Few short answers:
>  
> · No sign of that happening at all and I cannot see it happening
> · No, existing Directives are repealed by the new Directives on the 
> dates indicated,  but you may wish to look at Recommended format for DoC that 
> can reference existing and new 
> Directives,http://ec.europa.eu/DocsRoom/documents/14886/attachments/1/translations/en/renditions/native
>  
> 
>   (referenced from 
> http://ec.europa.eu/growth/sectors/electrical-engineering/emc-directive/index_en.htm
>  
> 
>  )
> · ETSI are working hard on updating over 150 standards, some more 
> information available:
> o   https://docbox.etsi.org/Workshop/2015/201511_RED-WORKSHOP/ 
>  for 
> presentations from November workshop
> o   Work program on radio standards: 
> http://webapp.etsi.org/ena/cvp.asp?search=RADIO 
>  and a number of RED 
> standards have a been published or are available as final draft
> o   Work program on EMC standards: 
> http://webapp.etsi.org/ena/cvp.asp?Search=emc&Status=&Directive=&submit1=Get+Work+Items
>  
> 
> · Lists of HS for current standards can be used for new Directives 
> until new lists are published as per relevant article in the directive such 
> as article 27 of the 2014/35/EU LVD.
> · So far I’m aware of:
> o   LVD guidance on transition to new 
> LVD,http://ec.europa.eu/DocsRoom/documents/13141/attachments/1/translations/en/renditions/native
>  
> 
>  available 
> athttp://ec.europa.eu/growth/sectors/electrical-engineering/lvd-directive/index_en.htm
>  
> 
> o   RED guidance is being worked on, but RED is not mandatory until 2017 so 
> there is more time for this.  
> http://ec.europa.eu/DocsRoom/documents/11983/attachments/1/translations/en/renditions/pdf
>  
> 
>  provides guidance on transitions for equipment moving into and out of 
> R&TTE/RED.
> · No one is expecting anything.
>  
> Regards
> Charlie
>  
> Charlie Blackham
> Sulis Consultants Ltd
> Tel: +44 (0)7946 624317
> LinkedIn:  <>uk.linkedin.com/in/charlieblackham/ 
> 
> Web: www.sulisconsultants.com 
> Registered in England and Wales, number 05466247
>  
>  
>  
> From: Ronald Pickard [mailto:ronald.pick...@compoundphotonics.com 
> ] 
> Sent: 29 March 2016 23:46
> To: EMC-PSTC@LISTSERV.IEEE.ORG 
> Subject: [PSES] EU's new approach directive transitions
>  
> Hi to all, and especially to those that are knowledgeable of the EU’s 
> processes on this subject,
>  
> I know that this subject has been discussed before without resolution, but 
> the time is nearing the end of the transition periods of the EU’s new EMC, LV 
> and RE directives and I (I’m guessing I’m not alone) was wondering if anyone 
> knows what the EU intends to do when these directives reach beyond their 
> respective transition periods with no listed harmonized st

[PSES] SV: [PSES] SV: [PSES] Commom mode current vs. differential mode current and LISN

2016-03-31 Thread Amund Westin 
Forget my respond «Real part / Magnitude / absolute value  …”

It is not correct. I was contacted by a friendly list member who corrected me.

Best regards Amund

 

 

Fra: Buzuayene, Mekonen [mailto:mekonen.buzuay...@anritsu.com] 
Sendt: 31. mars 2016 15:01
Til: Amund Westin 
Emne: RE: [PSES] SV: [PSES] Commom mode current vs. differential mode current 
and LISN

 

"Real part / Magnitude" is not a true description of the "vertical line." 

 

i.e., "a+jb", has a "real part" and "reactive part" where "a" or "b" may or not 
be posstive value.  

"Magnitude" on the other hand is the resultant of a complex number ("a+jb").

 

Mekonen

 

Sent via the Samsung Galaxy Mega® 2, an AT&T 4G LTE smartphone



 Original message 
From: Amund Westin mailto:am...@westin-emission.no> 
> 
Date: 3/31/2016 5:10 AM (GMT-08:00) 
To: EMC-PSTC@LISTSERV.IEEE.ORG   
Subject: [PSES] SV: [PSES] Commom mode current vs. differential mode current 
and LISN 

Real part / Magnitude / absolute value  …

https://en.wikipedia.org/wiki/Absolute_value

Actually, what you see measuring by a spectrum analyzer 

 

#Amund

 

Fra: Pawson, James [mailto:james.paw...@echostar.com] 
Sendt: 31. mars 2016 12:36
Til: EMC-PSTC@LISTSERV.IEEE.ORG  
Emne: Re: [PSES] Commom mode current vs. differential mode current and LISN

 

In relation to this discussion, what is the significance of the vertical lines 
either side of the |L| or |N|?

Google doesn’t recognise it as a searchable term, possibly thinks it is a 
logical OR symbol?

Thanks

James

 

 

From: Elliott Martinson [mailto:elliott.martin...@etcconnect.com] 
Sent: 30 March 2016 22:05
To: EMC-PSTC@LISTSERV.IEEE.ORG  
Subject: Re: [PSES] Commom mode current vs. differential mode current and LISN

 

Sorry if this is being over exhausted.

 

I don’t think I’m straying far from the real-world here. Let’s say for sake of 
argument, CM and DM currents from a single source are necessarily 100% in 
phase, ignoring whether it’s true/false. In a real device of moderate 
complexity, I don’t see any reason why there can’t be more than one independent 
source of noise at a particular frequency. Whether differential-mode or 
common-mode noise dominates one source, the dominant modes of the other sources 
don’t follow. They also aren’t necessarily in phase with each other (they 
aren’t necessarily out of phase either). There’s an entire range of 
possibilities, all affecting the proportion of DM and CM noise required to 
account for measuring |L| = |N| at a particular frequency, meaning it could be 
all DM and no CM, it could be all CM and no DM, it could be equal parts both, 
60/40, or anything else between. The whole point of this hypothetical 
measurement is that we don’t know enough about the noise source(s) to begin 
with, so the assumption of a single source could be a bit of a leap, unless we 
do in fact know our source for sure (such as a switching circuit).

 

Personally, I disagree with stating a rule—whose truth depends on a number of 
assumptions—as fact without acknowledging and justifying those assumptions. 
I’ve read an EMC textbook by each of the authors to whom you referred (great 
books, btw), and they do argue that if |L| = |N| it follows that one must 
dominate. Neither acknowledges the assumption of either 0 or 180 degree phase 
difference between the two. The derived equations may be true, but the 
interpretation of their implications ignores the fact that a current can have a 
complex amplitude (i.e. phase shift).

 

The rule may just be stated backwards, mixing what follows from what. It’s not 
that if |L| and |N| are similar, either DM or CM must dominate. Rather, if 
either DM or CM dominates, |L| and |N| will be similar! …Besides, If |L| and 
|N| can be measured individually, that same current probe can also be used to 
measure |L+N| and |L-N| directly. No assumptions necessary ;)

 

 

ALSO,

How common-mode currents arise and predicting their behavior accurately isn’t 
always very easy to wrap my head around, so correct me if I’m completely wrong 
here:

Common-impedance coupling through parasitic resistance from a DM current leads 
to a common-mode voltage exactly in phase with that DM current. That CM voltage 
can then leak through stray capacitance as a CM current that’s out of phase 
with the DM current/CM voltage.

 

The above effect, if correct, is very unlikely to produce CM current of any 
significance, so the DM current will almost certainly dominate. It’s not an 
example of how |L| can equal |N| without CM or DM dominating but rather an 
example of CM current out of phase with DM current.

 





Elliott Martinson

Product Assurance Speciali

[PSES] SV: [PSES] Commom mode current vs. differential mode current and LISN

2016-03-31 Thread Amund Westin 
Real part / Magnitude / absolute value  .

https://en.wikipedia.org/wiki/Absolute_value

Actually, what you see measuring by a spectrum analyzer 

 

#Amund

 

Fra: Pawson, James [mailto:james.paw...@echostar.com] 
Sendt: 31. mars 2016 12:36
Til: EMC-PSTC@LISTSERV.IEEE.ORG
Emne: Re: [PSES] Commom mode current vs. differential mode current and LISN

 

In relation to this discussion, what is the significance of the vertical
lines either side of the |L| or |N|?

Google doesn't recognise it as a searchable term, possibly thinks it is a
logical OR symbol?

Thanks

James

 

 

From: Elliott Martinson [mailto:elliott.martin...@etcconnect.com] 
Sent: 30 March 2016 22:05
To: EMC-PSTC@LISTSERV.IEEE.ORG  
Subject: Re: [PSES] Commom mode current vs. differential mode current and
LISN

 

Sorry if this is being over exhausted.

 

I don't think I'm straying far from the real-world here. Let's say for sake
of argument, CM and DM currents from a single source are necessarily 100% in
phase, ignoring whether it's true/false. In a real device of moderate
complexity, I don't see any reason why there can't be more than one
independent source of noise at a particular frequency. Whether
differential-mode or common-mode noise dominates one source, the dominant
modes of the other sources don't follow. They also aren't necessarily in
phase with each other (they aren't necessarily out of phase either). There's
an entire range of possibilities, all affecting the proportion of DM and CM
noise required to account for measuring |L| = |N| at a particular frequency,
meaning it could be all DM and no CM, it could be all CM and no DM, it could
be equal parts both, 60/40, or anything else between. The whole point of
this hypothetical measurement is that we don't know enough about the noise
source(s) to begin with, so the assumption of a single source could be a bit
of a leap, unless we do in fact know our source for sure (such as a
switching circuit).

 

Personally, I disagree with stating a rule-whose truth depends on a number
of assumptions-as fact without acknowledging and justifying those
assumptions. I've read an EMC textbook by each of the authors to whom you
referred (great books, btw), and they do argue that if |L| = |N| it follows
that one must dominate. Neither acknowledges the assumption of either 0 or
180 degree phase difference between the two. The derived equations may be
true, but the interpretation of their implications ignores the fact that a
current can have a complex amplitude (i.e. phase shift).

 

The rule may just be stated backwards, mixing what follows from what. It's
not that if |L| and |N| are similar, either DM or CM must dominate. Rather,
if either DM or CM dominates, |L| and |N| will be similar! .Besides, If |L|
and |N| can be measured individually, that same current probe can also be
used to measure |L+N| and |L-N| directly. No assumptions necessary ;)

 

 

ALSO,

How common-mode currents arise and predicting their behavior accurately
isn't always very easy to wrap my head around, so correct me if I'm
completely wrong here:

Common-impedance coupling through parasitic resistance from a DM current
leads to a common-mode voltage exactly in phase with that DM current. That
CM voltage can then leak through stray capacitance as a CM current that's
out of phase with the DM current/CM voltage.

 

The above effect, if correct, is very unlikely to produce CM current of any
significance, so the DM current will almost certainly dominate. It's not an
example of how |L| can equal |N| without CM or DM dominating but rather an
example of CM current out of phase with DM current.

 

 


Elliott Martinson

Product Assurance Specialist I

Electronic Theatre Controls

3031 N PLEASANT VIEW RD

MIDDLETON WI 53562-4809

Work: 608.824.5696 / Cell: 608.209.9897

elliott.martin...@etcconnect.com

 

From: John Woodgate [mailto:jmw1...@btinternet.com] 
Sent: Wednesday, March 30, 2016 9:09 AM
To: Elliott Martinson mailto:elliott.martin...@etcconnect.com> >
Subject: RE: [PSES] Commom mode current vs. differential mode current and
LISN

 

I wouldn't want to conjecture whether something *might* happen. Real-world
issues are enough, I think. You could look at the textbooks by Henry Ott and
Clayton R Paul for more general studies.

 

With best wishes OOO - Own Opinions Only  
www.jmwa.demon.co.uk

J M Woodgate and Associates Rayleigh England

 

From: Elliott Martinson [ 
mailto:elliott.martin...@etcconnect.com] 
Sent: Wednesday, March 30, 2016 3:01 PM
To: John Woodgate <  jmw1...@btinternet.com>
Subject: RE: [PSES] Commom mode current vs. differential mode current and
LISN

 

Possibly. I am certainly no expert-in fact I only just found out EMC exists
shortly before getting my most recent job last July.

 

Could common-impedance coupling from a purely capacitive or inductive
impedance in the retur

Re: [PSES] Commom mode current vs. differential mode current and LISN

2016-03-31 Thread Pawson, James 
In relation to this discussion, what is the significance of the vertical lines 
either side of the |L| or |N|?
Google doesn't recognise it as a searchable term, possibly thinks it is a 
logical OR symbol?
Thanks
James


From: Elliott Martinson [mailto:elliott.martin...@etcconnect.com]
Sent: 30 March 2016 22:05
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Commom mode current vs. differential mode current and LISN

Sorry if this is being over exhausted.

I don't think I'm straying far from the real-world here. Let's say for sake of 
argument, CM and DM currents from a single source are necessarily 100% in 
phase, ignoring whether it's true/false. In a real device of moderate 
complexity, I don't see any reason why there can't be more than one independent 
source of noise at a particular frequency. Whether differential-mode or 
common-mode noise dominates one source, the dominant modes of the other sources 
don't follow. They also aren't necessarily in phase with each other (they 
aren't necessarily out of phase either). There's an entire range of 
possibilities, all affecting the proportion of DM and CM noise required to 
account for measuring |L| = |N| at a particular frequency, meaning it could be 
all DM and no CM, it could be all CM and no DM, it could be equal parts both, 
60/40, or anything else between. The whole point of this hypothetical 
measurement is that we don't know enough about the noise source(s) to begin 
with, so the assumption of a single source could be a bit of a leap, unless we 
do in fact know our source for sure (such as a switching circuit).

Personally, I disagree with stating a rule-whose truth depends on a number of 
assumptions-as fact without acknowledging and justifying those assumptions. 
I've read an EMC textbook by each of the authors to whom you referred (great 
books, btw), and they do argue that if |L| = |N| it follows that one must 
dominate. Neither acknowledges the assumption of either 0 or 180 degree phase 
difference between the two. The derived equations may be true, but the 
interpretation of their implications ignores the fact that a current can have a 
complex amplitude (i.e. phase shift).

The rule may just be stated backwards, mixing what follows from what. It's not 
that if |L| and |N| are similar, either DM or CM must dominate. Rather, if 
either DM or CM dominates, |L| and |N| will be similar! ...Besides, If |L| and 
|N| can be measured individually, that same current probe can also be used to 
measure |L+N| and |L-N| directly. No assumptions necessary ;)


ALSO,
How common-mode currents arise and predicting their behavior accurately isn't 
always very easy to wrap my head around, so correct me if I'm completely wrong 
here:
Common-impedance coupling through parasitic resistance from a DM current leads 
to a common-mode voltage exactly in phase with that DM current. That CM voltage 
can then leak through stray capacitance as a CM current that's out of phase 
with the DM current/CM voltage.

The above effect, if correct, is very unlikely to produce CM current of any 
significance, so the DM current will almost certainly dominate. It's not an 
example of how |L| can equal |N| without CM or DM dominating but rather an 
example of CM current out of phase with DM current.


Elliott Martinson
Product Assurance Specialist I
Electronic Theatre Controls
3031 N PLEASANT VIEW RD
MIDDLETON WI 53562-4809
Work: 608.824.5696 / Cell: 608.209.9897
elliott.martin...@etcconnect.com

From: John Woodgate [mailto:jmw1...@btinternet.com]
Sent: Wednesday, March 30, 2016 9:09 AM
To: Elliott Martinson 
mailto:elliott.martin...@etcconnect.com>>
Subject: RE: [PSES] Commom mode current vs. differential mode current and LISN

I wouldn't want to conjecture whether something *might* happen. Real-world 
issues are enough, I think. You could look at the textbooks by Henry Ott and 
Clayton R Paul for more general studies.

With best wishes OOO - Own Opinions Only 
www.jmwa.demon.co.uk
J M Woodgate and Associates Rayleigh England

From: Elliott Martinson [mailto:elliott.martin...@etcconnect.com]
Sent: Wednesday, March 30, 2016 3:01 PM
To: John Woodgate mailto:jmw1...@btinternet.com>>
Subject: RE: [PSES] Commom mode current vs. differential mode current and LISN

Possibly. I am certainly no expert-in fact I only just found out EMC exists 
shortly before getting my most recent job last July.

Could common-impedance coupling from a purely capacitive or inductive impedance 
in the return cause common-mode noise that's exactly out of phase with the 
differential-mode noise? That sounds really unlikely at low frequency where 
resistance is significant, but at high frequency, maybe on a thin return 
conductor?

Elliott Martinson
Product Assurance Specialist I
Electronic Theatre Controls
3031 N PLEASANT VIEW RD
MIDDLETON WI 53562-4809
Work: 608.824.5696 / Cell: 608.209.9897
elliott.martin...@etcconnect.com

From: John Woodgate [mailto:jmw1...@btinternet.com]
Sent: W