Re: Question: Discharge capacitance 0.1 uF

[Warren Birmingham]

Many line filters do indeed have a bleeder resistor built in.  There 
are a few which do not, and I am familiar with one Delta filter that 
does not.  We added the bleeder across the terminals of the filter and 
it was approved by UL.  It just has to be done in accordance with 
accepted construction practices.

This particular filter is and IEC plug type so the leads are not 
saliently exposed unless the cord is left attached.  None the less I 
agree with John that it is not a good idea to ignore because one 
instance will get you a lot of word-of-mouth bad press and sales are 
hard-enough to come by so to speak.

Warren Birmingham
Epsilon-Mu Consultants
(510) 793-4806
email: war...@epsilon-mu.com
website: http://www.epsilon-mu.com



On Wednesday, Sep 18, 2002, at 10:11 US/Pacific, John Allen wrote:

> Hello Folks
>
> Tomonori Sato  commented "However, I think discharge from 0.1uF 
> capacitor charged to the mains peak voltage can be quite 
> uncomfortable."
>
> I believe that to be true from personal experience and from having to 
> investigate the results of a number of such incidents, and so would 
> remind member of a point that I made several years ago on this forum:
>
> The primary shock almost certainly will NOT hurt a person, but the 
> involuntary reaction TO the shock may well have much more 
> seriousconsequences.
>
> This type of shock is often encountered by people who pick up 
> equipment which they have just unplugged from the AC mains in order to 
> carry it elsewhere.  If they then touch the pins of the plug there are 
> numerous reported incidences of them involuntarily dropping the unit - 
> and that can possibly be on their own feet - and from a height of 
> about 3ft/1m! If the unit is more than a couple of pounds (about one 
> kilo) then the injury to t! he feet can be substantial.
>
> Worse situations could occur in industrial equipment when a service 
> engineer opens a cabinet to perform a service operation - the reaction 
> from the "shock" could cause him to strike touch other hazardous 
> electrical or mechanical parts (which probably should also not be 
> there, I do agree!) which then cause him serious actual injury.
>
> These types of incident do not make the equipment supplier very 
> "popular" to say the least, and could result in product liability 
> claims.
>
> The main basis for the claims would be that the supplier had not 
> adequately assessed the hazards and taken the appropriate simple 
> precautions which are easily and cheaply available - fit a bleeder 
> resistor across the capacitor, or use a filter with a resistor already 
> built in (or with transformer/inductor windings directly across the 
> capacitor - which achieve the same result) !
>
> Again from personal experience I can say that it is a very 
> "embarassing" and un! comfortable experience to have to write to an 
> injured or anno! yed person, or to his employer, to say "sorry, but 
> that is what the safety standard allows". It is just not good 
> "business sense".
>
> Therefore, regardless of the requirements of the various standards and 
> this argument over capacitor value and/or charging voltage, I firmly 
> believe that the use of bleeder resistors should be considered 
> effectively mandatory, and have always recommended it to engineers I 
> have advised on product safety.
>
> Regards
>
> John Allen
> Technical Consultant
> Electromagnetics, Safety and Reliability Group
> ERA Technology Ltd
> Cleeve Rd
> Leatherhead
> Surrey KT22 7SA
> Tel:  +44 (0) 1372-367025 (Direct)
> +44 (0) 1372-367000 (Switchboard)
> Fax:  +44 (0) 1372-367102 (Fax)
>
> --
> Replies to this message may be posted in the following public forum:
> Question: Discharge capacitance 0.1 uF
>
>
>
>


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Re: Current from Car 12V cigarette lighter socket

[Ken Javor]

Eichner informed me that indeed, I have been scooped by the SAE and this in
the works.

--
>From: John Woodgate 
>To: emc-p...@majordomo.ieee.org
>Subject: Re: Current from Car 12V cigarette lighter socket
>Date: Wed, Sep 18, 2002, 4:33 PM
>

>
> I read in !emc-pstc that Ken Javor  wrote
> (in <0h2n005m8hj...@mtaout04.icomcast.net>) about 'Current from Car 12V
> cigarette lighter socket' on Wed, 18 Sep 2002:
>
>>An excellent post.  Seems like a solution here would be for the newer
>>electrical outlet to be designed differently and not mate with the older
>>male cigarette lighter insert, and then provide an adapter that would take
>>the cigarette lighter insert to the new electrical outlet.  Then the 8 Amp
>>limit could be relaxed for appliances with the new plug, and any old devices
>>would still be taken care of.
>
> And your next question, for $64 000, is, 'Why didn't SAE think of that?'
> (;-)
> --
> Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
> Interested in professional sound reinforcement and distribution? Then go to
> http://www.isce.org.uk
> PLEASE do NOT copy news posts to me by E-MAIL!
>
> ---
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Re: Question: Discharge capacitance 0.1 uF

[T.Sato]

On Fri, 6 Sep 2002 16:19:52 +0900,
  "Michael Jang"  wrote:

> I have a question for "Discharge of capacitors in the primary circuit'
> (Related to 60950 standard)
> 
> Standard 
> Equipment is considered to comply if any capacitor having a marked or nominal
> capacitance exceeding 0.1 uF and connected to the PRIMARY CIRCUIT has a
> means of discharge resulting in a time constant not exceeding:
> - 1 s for Pluggable equipment type A; and
> - 10 s for Permanently connected equipment and for pluggable equipment type B.
> ---
> 
> Why does not consider up to 0.1 uF?

# maybe too late, but...

I think we can apply the limits for Limited Current Circuit to
capacitors connected to the primary circuit, too, and capacitors
up to 0.1uF are considered there.

A capacitor which:

  - capacitance <= 0.1uF for voltage <= 450V, or
  - stored charge <= 45uC for 450V < voltage <= 15kV, or
  - stored energy <= 350mJ for 15kV < voltage.

will become a Limited Current Circuit (2.4.1).

So, for voltage up to 450V d.c. (i.e. up to 318V a.c.), capacitor
up to 0.1uF will become a Limited Current Circuit, hence the voltage
is not Hazardous Voltage (1.2.8.4) - no additional condition would
be required for the capacitor connected to the primary circuit.

However, capacitor larger than 0.1uF would not comply with the
requirements for Limited Current Circuit, and the voltage could be
thought as Hazardous Voltage.
I think that is why the discharge requirement which, under certain
condition, allow capacitor exceeding 0.1uF connected to the primary
circuit was specified.

Regards,
Tom

--
Tomonori Sato  
URL: http://member.nifty.ne.jp/tsato/

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Re: Immunity severity levels

[Joe P Martin]

Alan,

Level 1:  (1V/M)Low-level electromagnetic radiation environment.
Levels typical of local radio/television stations located at more than 1
km, and transmitters/receivers of low power.

Level 2:  (3V/M)Moderate electromagnetic radiation environment.  Low
power portable transceivers (typically less than 1 W rating) are in use,
but with restrictions on use in close proximity to the equipment.  A
typical commercial environment.

Level 3:  (10V/M)   Severe electromagnetic radiation environment.  Portable
transceivers (2 W rating or more) are in use relatively close to the
equipment but not less than 1m.   High power broadcast transmitters are in
close proximity to the equipment and ISM equipment may be located close by.
A typical industrial environment.

Level x:  (Special) Level x is an open level which might be negotiated and
specified in the product standard or equipment specification.

Regards

Joe Martin
Applied Biosystems




  
alan.hud...@amsjv.com   
  
Sent by:   To: 
emc-p...@majordomo.ieee.org
owner-emc-pstc@majordomcc:  
  
o.ieee.org Subject: Immunity 
severity levels  

  

  
09/18/2002 10:14 AM 
  
Please respond to   
  
alan.hudson 
  

  

  






With regard to radiated emission immunity and EN61000-4-3 (or IEC 801-3)
I believe there are different field strengths used, depending on the
environment in which the apparatus being tested is to be used.

I believe equipment to be used in a well-protected environment may be
tested at a lower immunity level than equipment to be used in an
unprotected environment.

I've ordered a copy of 61000-4-3, but while I'm waiting I'd like to know
ASAP:

1) What are the definitions of the levels?
2) What field strengths  are used for the various levels? (I think level
2 is 3V/m and level 3 is 10V/m)

Regards,

Alan


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Re: Clock frequencies

[Joe P Martin]

Neil,

Section 15.33  of FCC Part 15 "Frequency Range of Radiated Measurements"
provides you with this information.

Regards

Joe Martin
Applied Biosystems




  
Neil Helsby 
  
cc:  
  
Sent by:   Subject: Clock 
frequencies 
owner-emc-pstc@majordom 
  
o.ieee.org  
  

  

  
09/18/2002 03:53 AM 
  
Please respond to Neil  
  
Helsby  
  

  

  





I read somewhere, and now cannot find, a reference to FCC requirements
with respect to the relationship between clock frequency and highest
emissions scan frequency.

Can anyone help, preferably pointing to the FCC document?

I also seem to remember similar comments being considered by the EU. Can
anyone advise on these?

Many thanks,

Neil Helsby


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RE: Immunity severity levels

[Aschenberg, Mat]

Please ignore my auto message. I am still refining it to prevent the
continual spam my employer can't seem to filter out. 
Sincerely, 
Mat Aschenberg

> -Original Message-
> From: John Woodgate [SMTP:j...@jmwa.demon.co.uk]
> Sent: Wednesday, September 18, 2002 2:59 PM
> To:   emc-p...@majordomo.ieee.org
> Subject:  Re: Immunity severity levels
> 
> 
> I read in !emc-pstc that alan.hud...@amsjv.com wrote (in <78431417180920
> 02/A03945/MULDER/1209944E2A00*@MHS>) about 'Immunity severity levels' on
> Wed, 18 Sep 2002:
> >With regard to radiated emission immunity and EN61000-4-3 (or IEC 801-3)
> >I believe there are different field strengths used, depending on the
> >environment in which the apparatus being tested is to be used.
> >
> >I believe equipment to be used in a well-protected environment may be
> >tested at a lower immunity level than equipment to be used in an
> >unprotected environment.
> >
> >I've ordered a copy of 61000-4-3, but while I'm waiting I'd like to know
> >ASAP:
> >
> >1) What are the definitions of the levels?
> >2) What field strengths  are used for the various levels? (I think level
> >2 is 3V/m and level 3 is 10V/m)
> 
> Although some would get the impression from the text that these levels
> are regulatory test levels, they are **guidance for product committees
> when writing product EMC standards** and have NO regulatory validity.
> You must use the level specified in the relevant product EMC standard
> (an EN55xxx standard) or the generic EN61000-6-x if there is no product
> standard.
> -- 
> Regards, John Woodgate, OOO - Own Opinions Only.
> http://www.jmwa.demon.co.uk 
> Interested in professional sound reinforcement and distribution? Then go
> to 
> http://www.isce.org.uk
> PLEASE do NOT copy news posts to me by E-MAIL!
> 
> ---
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RE: Clock frequencies

[Pettit, Ghery]

John,

Cable emissions seldom are a significant factor above 1 GHz.  Besides, we're
supposed to tune for maximum smoke, not minimum .

There are products on the market today that meet the FCC limits, but would
not meet the tighter limits being proposed.  There are no interference
complaints from these products.  What problem are we trying to fix with
limits tighter than the FCC's?

Ghery


-Original Message-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: Wednesday, September 18, 2002 1:53 PM
To: emc-p...@majordomo.ieee.org
Subject: Re: Clock frequencies



I read in !emc-pstc that Pettit, Ghery  wrote
(in )
about 'Clock frequencies' on Wed, 18 Sep 2002:
>CISPR SC I meets next week in Christchurch, New Zealand and this will be a
>topic of discussion at the meetings.  We on the US delegation will be
trying
>to keep the voices for tighter limits from being successful. 

It's really not something worth having a big argument about. To change
the measured result by 6 dB, just move one of the cables a few cm.

This Emperor really DOESN'T have any clothes.(;-)
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk

Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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Re: Current from Car 12V cigarette lighter socket

[John Woodgate]

I read in !emc-pstc that Ken Javor  wrote
(in <0h2n005m8hj...@mtaout04.icomcast.net>) about 'Current from Car 12V
cigarette lighter socket' on Wed, 18 Sep 2002:

>An excellent post.  Seems like a solution here would be for the newer 
>electrical outlet to be designed differently and not mate with the older
>male cigarette lighter insert, and then provide an adapter that would take
>the cigarette lighter insert to the new electrical outlet.  Then the 8 Amp
>limit could be relaxed for appliances with the new plug, and any old devices
>would still be taken care of.

And your next question, for $64 000, is, 'Why didn't SAE think of that?'
(;-)
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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Looking for work

[John Harrington]

Hello all

Sad to say I was made redundant yesterday so if any of you know of any 
positions available for a senior EMC engineer / manager with a load of 
experience in the commercial laboratory field please let me know at this email 
address.

Positions in the US, Canada or the UK preferred.

I'll send out my resume on request rather than flood the internet with unwanted 
kilobytes.

Thank you for the support you've provided me through this portal in the past 
few years.

Best regards

John Harrington

Re: Immunity severity levels

[Ken Javor]

Levels are 1, 3, and 10 V/m, but that is unmodulated.  The required 
modulation scheme (80% AM) adds a requirement for an extra 5 dB of headroom,
so that if the EUT responds to the peak of the modulation waveform (as most
electronic circuits do) the field intensities are effectively 1.8, 5.4, and
18 V/m.

--
>From: alan.hud...@amsjv.com
>To: emc-p...@majordomo.ieee.org
>Subject: Immunity severity levels
>Date: Wed, Sep 18, 2002, 12:14 PM
>

>
>
> With regard to radiated emission immunity and EN61000-4-3 (or IEC 801-3)
> I believe there are different field strengths used, depending on the
> environment in which the apparatus being tested is to be used.
>
> I believe equipment to be used in a well-protected environment may be
> tested at a lower immunity level than equipment to be used in an
> unprotected environment.
>
> I've ordered a copy of 61000-4-3, but while I'm waiting I'd like to know
> ASAP:
>
> 1) What are the definitions of the levels?
> 2) What field strengths  are used for the various levels? (I think level
> 2 is 3V/m and level 3 is 10V/m)
>
> Regards,
>
> Alan
>
>
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
>
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Re: Question: Discharge capacitance 0.1 uF

[Warren Birmingham]

Many line filters do indeed have a bleeder resistor built in.  There 
are a few which do not, and I am familiar with one Delta filter that 
does not.  We added the bleeder across the terminals of the filter and 
it was approved by UL.  It just has to be done in accordance with 
accepted construction practices.


This particular filter is and IEC plug type so the leads are not 
saliently exposed unless the cord is left attached.  None the less I 
agree with John that it is not a good idea to ignore because one 
instance will get you a lot of word-of-mouth bad press and sales are 
hard-enough to come by so to speak.


Warren Birmingham
Epsilon-Mu Consultants
(510) 793-4806
email: war...@epsilon-mu.com
website: http://www.epsilon-mu.com



On Wednesday, Sep 18, 2002, at 10:11 US/Pacific, John Allen wrote:


Hello Folks

Tomonori Sato  commented "However, I think discharge from 0.1uF 
capacitor charged to the mains peak voltage can be quite 
uncomfortable."


I believe that to be true from personal experience and from having to 
investigate the results of a number of such incidents, and so would 
remind member of a point that I made several years ago on this forum:


The primary shock almost certainly will NOT hurt a person, but the 
involuntary reaction TO the shock may well have much more 
seriousconsequences.


This type of shock is often encountered by people who pick up 
equipment which they have just unplugged from the AC mains in order to 
carry it elsewhere.  If they then touch the pins of the plug there are 
numerous reported incidences of them involuntarily dropping the unit - 
and that can possibly be on their own feet - and from a height of 
about 3ft/1m! If the unit is more than a couple of pounds (about one 
kilo) then the injury to t! he feet can be substantial.


Worse situations could occur in industrial equipment when a service 
engineer opens a cabinet to perform a service operation - the reaction 
from the "shock" could cause him to strike touch other hazardous 
electrical or mechanical parts (which probably should also not be 
there, I do agree!) which then cause him serious actual injury.


These types of incident do not make the equipment supplier very 
"popular" to say the least, and could result in product liability 
claims.


The main basis for the claims would be that the supplier had not 
adequately assessed the hazards and taken the appropriate simple 
precautions which are easily and cheaply available - fit a bleeder 
resistor across the capacitor, or use a filter with a resistor already 
built in (or with transformer/inductor windings directly across the 
capacitor - which achieve the same result) !


Again from personal experience I can say that it is a very 
"embarassing" and un! comfortable experience to have to write to an 
injured or anno! yed person, or to his employer, to say "sorry, but 
that is what the safety standard allows". It is just not good 
"business sense".


Therefore, regardless of the requirements of the various standards and 
this argument over capacitor value and/or charging voltage, I firmly 
believe that the use of bleeder resistors should be considered 
effectively mandatory, and have always recommended it to engineers I 
have advised on product safety.


Regards

John Allen
Technical Consultant
Electromagnetics, Safety and Reliability Group
ERA Technology Ltd
Cleeve Rd
Leatherhead
Surrey KT22 7SA
Tel:  +44 (0) 1372-367025 (Direct)
+44 (0) 1372-367000 (Switchboard)
Fax:  +44 (0) 1372-367102 (Fax)

--
Replies to this message may be posted in the following public forum:
Question: Discharge capacitance 0.1 uF







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Re: Medical equipment and EN61000-3-2

[John Woodgate]

I read in !emc-pstc that plaw...@west.net wrote (in ) about 'Medical equipment and EN61000-3-2' on
Wed, 18 Sep 2002:
>Or are their different levels of hospitals, some fed by LV transformers, some
>fed by MV transformers?

Yes.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
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Re: Breaker panel lockout-tagout

[Warren Birmingham]

I'm not an authority, but I would think that this is against both the 
fire code and common sense.  If an emergency developed such as electric 
shock or fire and the breaker could not be manually opened, i see it as 
tantamount to the locking of fire escape doors and many liability 
concerns.  The object of locking out a single breaker is to prevent 
THAT breaker from being energized accidently.


Warren Birmingham
Epsilon-Mu Consultants
(510) 793-4806
email: war...@epsilon-mu.com
website: http://www.epsilon-mu.com


On Wednesday, Sep 18, 2002, at 10:29 US/Pacific, lcr...@tuvam.com wrote:


Group,

Is anyone aware of an authoritative position on the acceptability (or 
not) of applying a lock to a breaker panel cover (and so affecting 
access to other, unrelated, breakers behind the same cove) to achieve 
OSHA compliant Lockout/Tagout rather than applying the lock to breaker 
directly?


-Lauren Crane
TUV America





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RE: USB Immunity Specs??

[rbusche]

In the computer simulation business we are moving towards various PC solutions 
at the request of our customers. These PCs are used in environments that have 
been defined as "Heavy Industrial" by our customers and the test organizations 
that validate the systems in the field. 

This forces us to put commercial PCs into a 10V/m or 10V test environment. So 
what is the solution? I would be interested to see how the issues Brian Kunde 
identified are being addressed and what changes we will see if the future?

Rick Busche
Evans & Sutherland
rbus...@es.com

-Original Message-
From: david_ster...@ademco.com [mailto:david_ster...@ademco.com]
Sent: Wednesday, September 18, 2002 2:54 PM
To: brian_ku...@leco.com; emc-p...@majordomo.ieee.org
Subject: RE: USB Immunity Specs??



Brian -
USB on a PC is designed for residential environment;  stress levels should
be 3V/m for EN61000-4-3 and 3V for EN61000-4-6.  

We got similar results checking USB to EN50130-4 alarm system requirements
(which resemble industrial environment.  EFT needs fault-tolerant software
(acceptable performance loss).
Alarm P/F criteria are slightly different:  no false alarms or change of
state (armed to unarmed and vice-versa).  Fault tolerant software is not
acceptable for all alarm applications.

David

-Original Message-
From: brian_ku...@leco.com [mailto:brian_ku...@leco.com]
Sent: Wednesday, September 18, 2002 3:02 PM
To: emc-p...@majordomo.ieee.org
Subject: USB Immunity Specs??



Dear Group,

Our Engineering Department thinks that USB is the worlds best interface.
Though
it has a lot going for it, I'm not sure if is all that, but never the less,
I'm
seeing it used to control and interface with commercial and industrial
instrumentation requiring the more severe immunity testing for Europe; e.g.
10volt/meter Radiated Immunity, 10Vrms Conducted Immunity, and 2KV Fast
Transient Testing (1KV using Clamp).

To these higher levels, we have failed almost every USB system we have ever
encountered using USB cables longer than 2 meter in length.  I understand
that
USB is suppose to be able to goto 5 meter.  The failure shows itself as a
communication error that usually requires resetting the hardware.

Fairly recently we evaluated one of those "USB Hubs".  Someone realized that
if
you run a 5 meter USB cable into a HUB you can run it out another 5 meters.
Our
Immunity testing failed the HUB configuration in the most miserable ways.  A
detailed examination of the manual that came with the USB Hub proudly
displayed
a DOC and the CE marking, but gave no special conditions or mention of cable
lengths.

At home I  have a USB Flatbed scanner that came with a 2 meter USB cable
with
ferrite beads on BOTH ends.  What might I expect if I went to Best Buy and
bought a 5 meter USB cable and installed it on my scanner?  I guess I would
expect it NOT to comply with emissions requirements, who knows about
immunity,
but would it even function?  In any case, I don't think it is right that I
can
purchase a scanner and only when I get it home and open the box I find out
that
I can only use the provided 2 meter cable.  Being USB,  I expected to be
able to
put any 5 meter cable on it.  I hate surprises like that, don't you?

We have tested dozens of different USB cables, looking for a solution to the
Immunity Problems we are encountering (Even the Gold Plated 12MB/s versions
which tested no better than the cheep ones). We discovered that we could get
it
to pass Immunity if the impedance of the USB cable was improved.  We would
simulate this by going over a standard USB cable with a better, heavier
braided
shield and then soldering the shield to the backshells (connecting a ground
strap between the instrument and the computer would often give similar
results).
The problem with this approach is that no one makes a cable like this. I
understand that USB cables are constructed according to the USB standard
which
includes a DC cable shield impedance requirement which in my opinion should
be
lower and include impedance requirements for the entire frequency band.  

So, to all you USB Experts out there, please education me in the finer
points of
USB.

1. Does the USB specification take into account any Immunity Requirements?
If
so, to what levels?

2. Any recommendations to improve a USB systems performance during Immunity
Testing?

3. What are others doing?  I expect that they are testing with short USB
cables
then specifying (or not) the length in the user's manual.  

4. What changes can we expect to see in the future of USB? We know the
interface
is getting faster and faster.  Is functionality, cable length, Emissions,
and
Immunity being considered?  



Brian Kunde
LECO Corp.



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Re: CE Marking for Passive speakers

[John Woodgate]

I read in !emc-pstc that soundsu...@aol.com wrote (in <14f.143ddef3.2ab9
c...@aol.com>) about 'CE Marking for Passive speakers' on Wed, 18 Sep
2002:
>In a message dated 9/18/02 4:40:07 AM Eastern Daylight Time, 
>j...@jmwa.demon.co.uk writes:
>
>
>>   >>>Have you looked at a properly-labelled loudspeaker? Or the spec for 
>> a
>>   pair of headphones? Electrical ratings in there!
>
>
>I own four sets of passive loudspeakers, a passive subwoofer and two pairs 
>of headphones.  I don't know which, if any of them are "properly 
> labelled", 
>but none of them carry a voltage rating - which is what the scope criteria 
>of the LVD considers.  I'm sorry, but I'm ignorant of what EN 60065 says 
> on 
>the subject.  Is a voltage rating required on passive loudspeakers?    

No, but that is irrelevant. If a hazardous voltage can occur at the
input, there are requirements to be met. If not, the product conforms by
default. This is no different from any other case of 'conforms by
default because the controlled feature is not present'. An example would
be a TV without a stand, which does not have to conform to the
requirements for the stand!
>
>I cited EN60065 and the EMC Guidelines document.
>
>Which brings up an interesting questioncan we assume that the scope of 
>an EN standard is harmonized with the scope of a Directive?   For example, 
>if an EN standard includes requirements for a specific product (case in 
>point, passive loudspeaker), and the EN standard is listed in an Annex of 
>the LVD, is this grounds to conclude that the product is "clearly covered" 
>under the LVD?  I believe the answer is no.  

I doubt that what you believe is relevant.
>
>I think we should be careful to remember that it is the Directive that 
>establishes the legal scope of CE marking application and the EN standard 
> is 
>a voluntary instrument that can be used to establish compliance at the 
>manufacturer's discretion.

Yes, but you can't pick out bits that you choose not to comply with. If
you don't apply the standard, you have to show conformity another way,
which is usually much more difficult.

But why take the hard route? It isn't as if it was *difficult* to
conform and apply the CE mark. If it involved costly testing, I could
understand the reluctance, but it doesn't.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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Re: EN60065 mains switches

[John Woodgate]

I read in !emc-pstc that Colgan, Chris 
wrote (in ) about 'EN60065
mains switches' on Wed, 18 Sep 2002:
>I know that engineers familiar with EN60065 are rarer than hen's teeth but
>maybe someone out there can help me...
>
>Clause 14.6.2 allows for no mains switch to be fitted if the product can be
>switched on or off or both automatically.  Do you think that an audio
>amplifier that utilises an input signal detect circuit to automatically
>switch on fulfils the requirements of this clause?

You should be looking at the 2002 edition, in which 14.6.2 is not about
that. This 14.6 gets re-hashed in every edition, so you must use the up-
to-date edition. In this case, the relevant text is in 8.9.1! An all-
pole disconnect device is required, but it can be the mains plug or
appliance coupler. So your audio amplifier is quite OK - to the 2002
edition. Do you *really* want to know about how it would fare under the
previous edition? (;-)
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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Re: Clock frequencies

[John Woodgate]

I read in !emc-pstc that Pettit, Ghery  wrote
(in )
about 'Clock frequencies' on Wed, 18 Sep 2002:
>CISPR SC I meets next week in Christchurch, New Zealand and this will be a
>topic of discussion at the meetings.  We on the US delegation will be trying
>to keep the voices for tighter limits from being successful. 

It's really not something worth having a big argument about. To change
the measured result by 6 dB, just move one of the cables a few cm.

This Emperor really DOESN'T have any clothes.(;-)
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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Re: Immunity severity levels

[John Woodgate]

I read in !emc-pstc that alan.hud...@amsjv.com wrote (in <78431417180920
02/A03945/MULDER/1209944E2A00*@MHS>) about 'Immunity severity levels' on
Wed, 18 Sep 2002:
>With regard to radiated emission immunity and EN61000-4-3 (or IEC 801-3)
>I believe there are different field strengths used, depending on the
>environment in which the apparatus being tested is to be used.
>
>I believe equipment to be used in a well-protected environment may be
>tested at a lower immunity level than equipment to be used in an
>unprotected environment.
>
>I've ordered a copy of 61000-4-3, but while I'm waiting I'd like to know
>ASAP:
>
>1) What are the definitions of the levels?
>2) What field strengths  are used for the various levels? (I think level
>2 is 3V/m and level 3 is 10V/m)

Although some would get the impression from the text that these levels
are regulatory test levels, they are **guidance for product committees
when writing product EMC standards** and have NO regulatory validity.
You must use the level specified in the relevant product EMC standard
(an EN55xxx standard) or the generic EN61000-6-x if there is no product
standard.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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Re: EN60065 mains switches

[John Woodgate]

I read in !emc-pstc that Tyra, John  wrote (in
<418fbd441c22d5118d860003470d43160543e...@cupid.bose.com>) about
'EN60065 mains switches' on Wed, 18 Sep 2002:

>Also be aware that the published 7th edition of IEC60065 eliminates the need
>for a switch which is in line with the current edition of UL6500.
>Unfortunately it will probably be several years before all the countries
>adopt this edition of the standard

It is already adopted as EN 60065:2002. If it hasn't already been
'notified' in the Official Journal, it soon will be.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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RE: USB Immunity Specs??

[David_Sterner]

Brian -
USB on a PC is designed for residential environment;  stress levels should
be 3V/m for EN61000-4-3 and 3V for EN61000-4-6.  

We got similar results checking USB to EN50130-4 alarm system requirements
(which resemble industrial environment.  EFT needs fault-tolerant software
(acceptable performance loss).
Alarm P/F criteria are slightly different:  no false alarms or change of
state (armed to unarmed and vice-versa).  Fault tolerant software is not
acceptable for all alarm applications.

David

-Original Message-
From: brian_ku...@leco.com [mailto:brian_ku...@leco.com]
Sent: Wednesday, September 18, 2002 3:02 PM
To: emc-p...@majordomo.ieee.org
Subject: USB Immunity Specs??



Dear Group,

Our Engineering Department thinks that USB is the worlds best interface.
Though
it has a lot going for it, I'm not sure if is all that, but never the less,
I'm
seeing it used to control and interface with commercial and industrial
instrumentation requiring the more severe immunity testing for Europe; e.g.
10volt/meter Radiated Immunity, 10Vrms Conducted Immunity, and 2KV Fast
Transient Testing (1KV using Clamp).

To these higher levels, we have failed almost every USB system we have ever
encountered using USB cables longer than 2 meter in length.  I understand
that
USB is suppose to be able to goto 5 meter.  The failure shows itself as a
communication error that usually requires resetting the hardware.

Fairly recently we evaluated one of those "USB Hubs".  Someone realized that
if
you run a 5 meter USB cable into a HUB you can run it out another 5 meters.
Our
Immunity testing failed the HUB configuration in the most miserable ways.  A
detailed examination of the manual that came with the USB Hub proudly
displayed
a DOC and the CE marking, but gave no special conditions or mention of cable
lengths.

At home I  have a USB Flatbed scanner that came with a 2 meter USB cable
with
ferrite beads on BOTH ends.  What might I expect if I went to Best Buy and
bought a 5 meter USB cable and installed it on my scanner?  I guess I would
expect it NOT to comply with emissions requirements, who knows about
immunity,
but would it even function?  In any case, I don't think it is right that I
can
purchase a scanner and only when I get it home and open the box I find out
that
I can only use the provided 2 meter cable.  Being USB,  I expected to be
able to
put any 5 meter cable on it.  I hate surprises like that, don't you?

We have tested dozens of different USB cables, looking for a solution to the
Immunity Problems we are encountering (Even the Gold Plated 12MB/s versions
which tested no better than the cheep ones). We discovered that we could get
it
to pass Immunity if the impedance of the USB cable was improved.  We would
simulate this by going over a standard USB cable with a better, heavier
braided
shield and then soldering the shield to the backshells (connecting a ground
strap between the instrument and the computer would often give similar
results).
The problem with this approach is that no one makes a cable like this. I
understand that USB cables are constructed according to the USB standard
which
includes a DC cable shield impedance requirement which in my opinion should
be
lower and include impedance requirements for the entire frequency band.  

So, to all you USB Experts out there, please education me in the finer
points of
USB.

1. Does the USB specification take into account any Immunity Requirements?
If
so, to what levels?

2. Any recommendations to improve a USB systems performance during Immunity
Testing?

3. What are others doing?  I expect that they are testing with short USB
cables
then specifying (or not) the length in the user's manual.  

4. What changes can we expect to see in the future of USB? We know the
interface
is getting faster and faster.  Is functionality, cable length, Emissions,
and
Immunity being considered?  



Brian Kunde
LECO Corp.



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RE: Current from Car 12V cigarette lighter socket

[Jim Eichner]

Thanks.

The solution you propose is in the works.  The SAE is working on a
completely different style connector for power connections to 12Vdc, and 2
other styles for 42Vdc and 120Vac connectors.  This effort is just getting
off the ground however.

Jim Eichner, P.Eng. 
Manager, Engineering Services 
Xantrex Technology Inc. 
e-mail: jim.eich...@xantrex.com 
web: www.xantrex.com 
Any opinions expressed are those of my invisible friend, who really exists.
Honest.  No really.
Confidentiality Notice: This email message, including any attachments, is
for the sole use of the intended recipient(s) and may contain confidential
and privileged information. Any unauthorized review, use, disclosure or
distribution is prohibited. If you are not the intended recipient, please
contact the sender by reply e-mail and destroy all copies of the original
message.





-Original Message-
From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Wednesday, September 18, 2002 1:14 PM
To: Jim Eichner; 'EMC-PSTC - forum'
Subject: Re: Current from Car 12V cigarette lighter socket


An excellent post.  Seems like a solution here would be for the newer 
electrical outlet to be designed differently and not mate with the older
male cigarette lighter insert, and then provide an adapter that would take
the cigarette lighter insert to the new electrical outlet.  Then the 8 Amp
limit could be relaxed for appliances with the new plug, and any old devices
would still be taken care of.

--
>From: Jim Eichner 
>To: "'EMC-PSTC - forum'" 
>Subject: RE: Current from Car 12V cigarette lighter socket
>Date: Wed, Sep 18, 2002, 1:47 PM
>

>
> UL2089 covers appliance using the socket.  There is no UL or CSA standard
> covering the socket itself, but there is SAE J563, which provided
dimensions
> and limits the continuous current drawn through lighter sockets by
> appliances to 8Adc.
>
> The intent is to protect the wiring in behind the lighter socket, because
> that wiring is based on an intermittent 10-15A load (how often do you
light
> a cigarette?) and is therefore undersized for its overcurrent protection.
> In a sample of 7 or 8 cigarette lighter sockets and wiring harnesses that
I
> pulled out of different makes of car in the mid 90's, I found wire sizes
> ranging from No. 16AWG to 22AWG, being protected by fuses ranging from 15
to
> 30A!
>
> In the world of continuous 12Vdc loads - aftermarket accessories like
> chargers for cell phones and laptops, in-your-car coffee makers and vacuum
> cleaners, etc - we need to know what continuous load the lighter socket
and
> its harness can sustain.  The SAE pegs this at 8A and UL and CSA are
> enforcing that limit, both in what they will allow a 12Vdc appliance to
> draw, and in requiring a max. 8A fuse in the lighter plug.
>
> Recognizing the limitations on lighter sockets, the automotive industry
has
> come up with the "power point": a cylindrical connector based on the
> cigarette lighter socket but designed, fused, wired, and rated for
> continuous loads and lacking the bimetal fingers that release the lighter
> plug when it's hot.  These are usually rated for 15-20Adc continuous,
> allowing designers to be free of the 8A limit. In theory.
>
> However, since the male plugs on 12Vdc automotive appliances will fit both
> the true lighter socket and these newer power points, UL and CSA will not
> back down (nor should they) from the 8A limit for a 12Vdc appliance
equipped
> with a male plug that fits a lighter socket.  They also will not accept a
> marking such as "Use only with power points, not with lighter sockets"
> because too many cars only have lighter sockets.
>
> Not sure you're trying to do anything with that kind of power level, but
you
> should be aware of the limitations.
>
> Regards,
>
> Jim Eichner, P.Eng.
> Manager, Engineering Services
> Xantrex Technology Inc.
> e-mail: jim.eich...@xantrex.com
> web: www.xantrex.com
> Any opinions expressed are those of my invisible friend, who really
exists.
> Honest.  No really.
>
> Confidentiality Notice: This email message, including any attachments, is
> for the sole use of the intended recipient(s) and may contain confidential
> and privileged information. Any unauthorized review, use, disclosure or
> distribution is prohibited. If you are not the intended recipient, please
> contact the sender by reply e-mail and destroy all copies of the original
> message.
>
>
>
>
> -Original Message-
> From: Ron Baugh [mailto:ron...@verifone.com]
> Sent: Wednesday, September 18, 2002 3:41 AM
> To: 'Charles Blackham'; 'emc-p...@majordomo.ieee.org'
> Subject: RE: Current from Car 12V cigarette lighter socket
>
>
>
> Yes Charles it's UL 2089 "Vehicle Battery Adapters."  I also have a unit
> (ITE
> Listed) that will operate from a auto battery and I have to make sure that
> all
> my 12V devices meets this standard.
>
> Ron Baugh
> VeriFone, Inc.
>  -Original Message-
>  From: Charles Blackham [SMTP:cblac...@airspan.com]
>  Sent:

Re: Medical equipment and EN61000-3-2

[dave . osborn]

Hello Patrick,

In most of the developed world hospitals have their own  (non-public) 
low-voltage distribution system.

They have their own distribution transformer(s) and parts of the system may be 
floating (e.g. European operating theatres) while other parts have emergency 
back-up systems (certain OR or critical care outlets).

Hospitals, just like large office buildings are rarely directly connected to 
the public low-voltage distribution system.  Their electricity is normally 
provided by a MV transformer.

This is not necessary true in lesser developed countries.

Best regards,

Dave Osborn
PM-CMS
Philips Medical Systems
+1 978 659 3178
fax +1 978 685 5624
dave.osb...@philips.com




  plaw...@west.net  

  Sent by:   To:  EMC-PSTC 
 
 
  owner-emc-pstc@majordo cc:  (bcc: Dave 
Osborn/ANR/MS/PHILIPS)  
   
  mo.ieee.orgSubject:   Medical 
equipment and EN61000-3-2   



 Classification:

  09/18/2002 03:55 PM   

  Please respond to 

  plawler   










The scope of EN61000-3-2:2001 says that the standard deals with harmonic
currents injected into the public low-voltage distribution system.

I can see that residences and offices are connected to the public system.
However, I don't know about distribution to hospitals.

Are their power requirements specialized enough that their electricity is
provided by a MV transformer?  This would exempt hospital-only medical products
from the harmonic current requirements.
Or are their different levels of hospitals, some fed by LV transformers, some
fed by MV transformers?

Patrick Lawler
plaw...@west.net

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Re: Distributors of Medical Devices in Europe

[jgriver]

Mark,

I assume that you mean Class 1 according to the EU's Medical Devices 
Directive, and not the FDA classification. Although the principle is 
the same, i.e. Class 1 is low-risk, the classification method is not 
identical.

The MDD deals with the device rather than the distributor. Compliance 
of the device with the MDD is mandatory. You should probably check 
the Health Ministry or 'Competant Authority' (as defined in the MDD), 
to check whether there are requirements on the distributor. As this 
subject is not covered by the MDD, the regulations are likely to be 
different in each country of the EU. You can contact the UK Competent 
Authority via their website at:

http://www.medical-devices.gov.uk/

Distributors would certainly be obligated to report incidents 
involving injury or death to the authorities.

I hope this helps.


Jon Griver
http://www.601help.com
The Medical Device Developer's Guide to IEC 60601-1



On 18 Sep 2002 at 8:11, Mark Schmidt wrote:

> 
> Hello Group,
> 
> Are there any requirements for European Distributors of Medical Devices, i.e. 
> license or registration. The Device in question is a Class 1 device.
> 
> Thank you.
> 
> Mark Schmidt
> Regulatory Compliance 
> X-Rite Incorporated 
> Grandville, MI 
> USA
> (616) 257 2469
> mschm...@xrite.com
> 
> 
> ---
> This message is from the IEEE EMC Society Product Safety
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Re: CE Marking for Passive speakers

[John Woodgate]

I read in !emc-pstc that Gert Gremmen  wrote (in
) about 'CE Marking
for Passive speakers' on Wed, 18 Sep 2002:
>Although your reasoning sounds valid, it's simply
>not accurate. Firts; The guidelines are not LAW
>
>"Guidelines are publicly available, but they are not binding in the sense of
>legal acts adopted by the Community. The legally binding provisions are
>those transposing the EMC Directive"

You are simply making unsubstantiated counter-assertions, of no
significant validity. There is no point in continuing a discussion on
those terms. My view is not just my personal view; it's that of
certified bodies in Britain.

Your assertion that a loudspeaker is equivalent to a cable is
unsustainable. They emit d.c. magnetic fields and some emit audio-
frequency magnetic fields. Some emit sound when subjected to an external
audio-frequency magnetic field, which could be interpreted as a lack of
immunity. The input terminals may carry hazardous voltages.

Why take the tough decision not to CE mark, when it costs very little to
do so and to print in the instructions the text that I previously
posted?
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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Re: Current from Car 12V cigarette lighter socket

[Ken Javor]

An excellent post.  Seems like a solution here would be for the newer 
electrical outlet to be designed differently and not mate with the older
male cigarette lighter insert, and then provide an adapter that would take
the cigarette lighter insert to the new electrical outlet.  Then the 8 Amp
limit could be relaxed for appliances with the new plug, and any old devices
would still be taken care of.

--
>From: Jim Eichner 
>To: "'EMC-PSTC - forum'" 
>Subject: RE: Current from Car 12V cigarette lighter socket
>Date: Wed, Sep 18, 2002, 1:47 PM
>

>
> UL2089 covers appliance using the socket.  There is no UL or CSA standard
> covering the socket itself, but there is SAE J563, which provided dimensions
> and limits the continuous current drawn through lighter sockets by
> appliances to 8Adc.
>
> The intent is to protect the wiring in behind the lighter socket, because
> that wiring is based on an intermittent 10-15A load (how often do you light
> a cigarette?) and is therefore undersized for its overcurrent protection.
> In a sample of 7 or 8 cigarette lighter sockets and wiring harnesses that I
> pulled out of different makes of car in the mid 90's, I found wire sizes
> ranging from No. 16AWG to 22AWG, being protected by fuses ranging from 15 to
> 30A!
>
> In the world of continuous 12Vdc loads - aftermarket accessories like
> chargers for cell phones and laptops, in-your-car coffee makers and vacuum
> cleaners, etc - we need to know what continuous load the lighter socket and
> its harness can sustain.  The SAE pegs this at 8A and UL and CSA are
> enforcing that limit, both in what they will allow a 12Vdc appliance to
> draw, and in requiring a max. 8A fuse in the lighter plug.
>
> Recognizing the limitations on lighter sockets, the automotive industry has
> come up with the "power point": a cylindrical connector based on the
> cigarette lighter socket but designed, fused, wired, and rated for
> continuous loads and lacking the bimetal fingers that release the lighter
> plug when it's hot.  These are usually rated for 15-20Adc continuous,
> allowing designers to be free of the 8A limit. In theory.
>
> However, since the male plugs on 12Vdc automotive appliances will fit both
> the true lighter socket and these newer power points, UL and CSA will not
> back down (nor should they) from the 8A limit for a 12Vdc appliance equipped
> with a male plug that fits a lighter socket.  They also will not accept a
> marking such as "Use only with power points, not with lighter sockets"
> because too many cars only have lighter sockets.
>
> Not sure you're trying to do anything with that kind of power level, but you
> should be aware of the limitations.
>
> Regards,
>
> Jim Eichner, P.Eng.
> Manager, Engineering Services
> Xantrex Technology Inc.
> e-mail: jim.eich...@xantrex.com
> web: www.xantrex.com
> Any opinions expressed are those of my invisible friend, who really exists.
> Honest.  No really.
>
> Confidentiality Notice: This email message, including any attachments, is
> for the sole use of the intended recipient(s) and may contain confidential
> and privileged information. Any unauthorized review, use, disclosure or
> distribution is prohibited. If you are not the intended recipient, please
> contact the sender by reply e-mail and destroy all copies of the original
> message.
>
>
>
>
> -Original Message-
> From: Ron Baugh [mailto:ron...@verifone.com]
> Sent: Wednesday, September 18, 2002 3:41 AM
> To: 'Charles Blackham'; 'emc-p...@majordomo.ieee.org'
> Subject: RE: Current from Car 12V cigarette lighter socket
>
>
>
> Yes Charles it's UL 2089 "Vehicle Battery Adapters."  I also have a unit
> (ITE
> Listed) that will operate from a auto battery and I have to make sure that
> all
> my 12V devices meets this standard.
>
> Ron Baugh
> VeriFone, Inc.
>  -Original Message-
>  From: Charles Blackham [SMTP:cblac...@airspan.com]
>  Sent: Wednesday, September 18, 2002 2:07 AM
>  To: 'emc-p...@majordomo.ieee.org'
>  Subject: Current from Car 12V cigarette lighter socket
>
>
>  Some of our equipment runs off 12Vdc. Typically this is provided by
> a UL
> Listed ac/dc power supply that meets the Limited Power Source requirement of
> IEC60950. We wish to be able to power this from the 12V "cigarette lighter"
> socket in a car:
>
>  Is there a standard that covers the output of 12V sockets in cars?
> Do
> they have to meet something similar to the Limited Power Source requirements
> of
> IEC60950?
>
>  regards
>
>  Charlie Blackham
>  Senior Approvals Engineer
>  Airspan Communications Ltd.
>  
>
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
>
> Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/
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>  Ron Pickard: 

RE: Question: Discharge capacitance 0.1 uF

[Gert Gremmen]

Hi John,

Though you are fully right theoretically, i think parts of your story are a
bit overdone.

Most people do not make a habit-of-disconnecting-their-heavy-equipment-while
carrying-it-over-their-feet-at-the-mains-voltage-phase-point-of-90-degrees-w
hile-actively-seeking- both
points-of-the-power-plug-simultaneously-within-the-discharge-time-of-a-paper
-capacitor
of-less-then-0.1-uF-often-enough-to-really-make-the-manufacturer-very-"popul
ar" as you say,
not to mention that they also need to react involuntary by dropping the
equipment..

I mean:  a lot of conditions need to be satisfied a lot of times.
(but i also know that exactly this is what happens when an accident arrives)

Most handheld equipment does not contain capacitors between
phases and/or ground  BEFORE the momentary mains switch (drills etc),
and in cabinets where the mains is connected permanently  or by big power
plugs, service people do not have a habit of touching the bare parts
that fast after disconnecting.

Lets try some numbers:

Paper capacitors (and they are as they need to be self healing) do not hold
their charge
that long. At a selfdischarge impedance of 10 M the discharge time equals 1
second.
After a number of self healing discharges the capacitor actually  has a
bleeding
resistor build in. Did you ever unfold (unroll) a filter cap after a few
years duty
and hold it to the light ? Literally 100's of tiny holes can be seen with
the naked eye.
Possibly a new cap may hold it's charge longer ?

If a human body is to function as a discharge path , under the premise that
the discharge
is to be felt substantially, a current of say 3.0 mA is required. This
requires at a charge
voltage of 300 Volts 100 K of human impedance. Time constant 10 mS (half a
period)
Thats peak current. Average current during this time span is much less .
If you are wet handed (not recommended) the peak current may rise
substantially
but the pulse with decreases propotionally, so does the effect. This effect
can easily
be verified with an experiment using your own pulse generator and a
inversely
connected mains transformer and a volunteer : that was me during a time
I won't explain in detail why i volunteered though ..;<)))

At a pulse with of 1 mS one may accept much higher voltages before anything
is noticed
then at 100 mS (BTW don't start with square waves, but sinus pulses)

If one takes out a mains plug and voluntarily tries to touch ground and
phase plug
contacts at least 1 S have been elapsed. I mean, imagine your self pulling
with one
hand and touching the pins with the same (as the other carries the heavy
equipment).
The capacitor would be almost discharged.

Possibly your experiences have  been based upon equipment with
other type of capacitors with much better dielectricum, but possibly
not the well established paper type X or Y type capacitor.

I DO support your point about the discharge resistor though. Any accident
prevented is a step forward on the world wide scale of safety..



Gert Gremmen

ce-test, qualified testing

 -Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Allen
Sent: woensdag 18 september 2002 19:11
To: emc-p...@majordomo.ieee.org
Subject: Question: Discharge capacitance 0.1 uF


  Hello Folks

  Tomonori Sato  commented "However, I think discharge from 0.1uF capacitor
charged to the mains peak voltage can be quite uncomfortable."

  I believe that to be true from personal experience and from having to
investigate the results of a number of such incidents, and so would remind
member of a point that I made several years ago on this forum:

  The primary shock almost certainly will NOT hurt a person, but the
involuntary reaction TO the shock may well have much more
seriousconsequences.

  This type of shock is often encountered by people who pick up equipment
which they have just unplugged from the AC mains in order to carry it
elsewhere.  If they then touch the pins of the plug there are numerous
reported incidences of them involuntarily dropping the unit - and that can
possibly be on their own feet - and from a height of about 3ft/1m! If the
unit is more than a couple of pounds (about one kilo) then the injury to t!
he feet can be substantial.

  Worse situations could occur in industrial equipment when a service
engineer opens a cabinet to perform a service operation - the reaction from
the "shock" could cause him to strike touch other hazardous electrical or
mechanical parts (which probably should also not be there, I do agree!)
which then cause him serious actual injury.

  These types of incident do not make the equipment supplier very "popular"
to say the least, and could result in product liability claims.

  The main basis for the claims would be that the supplier had not
adequately assessed the hazards and taken the appropriate simple precautions
which are easily and cheaply available - fit a bleeder resistor across th

RE: USB Immunity Specs??

[Pettit, Ghery]

Brian,

The products were likely tested to the requirements in EN 55024.  3 V/m
radiated immunity.  3 V conducted immunity.  500 V EFT.  That is the product
specific immunity standard for ITE, and USB is an ITE interface.  Thus, the
CE Marking was correctly placed on the product.  We seldom see problems with
USB ports on computers when tested at these levels.

Ghery Pettit
Intel


-Original Message-
From: brian_ku...@leco.com [mailto:brian_ku...@leco.com]
Sent: Wednesday, September 18, 2002 12:02 PM
To: emc-p...@majordomo.ieee.org
Subject: USB Immunity Specs??



Dear Group,

Our Engineering Department thinks that USB is the worlds best interface.
Though
it has a lot going for it, I'm not sure if is all that, but never the less,
I'm
seeing it used to control and interface with commercial and industrial
instrumentation requiring the more severe immunity testing for Europe; e.g.
10volt/meter Radiated Immunity, 10Vrms Conducted Immunity, and 2KV Fast
Transient Testing (1KV using Clamp).

To these higher levels, we have failed almost every USB system we have ever
encountered using USB cables longer than 2 meter in length.  I understand
that
USB is suppose to be able to goto 5 meter.  The failure shows itself as a
communication error that usually requires resetting the hardware.

Fairly recently we evaluated one of those "USB Hubs".  Someone realized that
if
you run a 5 meter USB cable into a HUB you can run it out another 5 meters.
Our
Immunity testing failed the HUB configuration in the most miserable ways.  A
detailed examination of the manual that came with the USB Hub proudly
displayed
a DOC and the CE marking, but gave no special conditions or mention of cable
lengths.

At home I  have a USB Flatbed scanner that came with a 2 meter USB cable
with
ferrite beads on BOTH ends.  What might I expect if I went to Best Buy and
bought a 5 meter USB cable and installed it on my scanner?  I guess I would
expect it NOT to comply with emissions requirements, who knows about
immunity,
but would it even function?  In any case, I don't think it is right that I
can
purchase a scanner and only when I get it home and open the box I find out
that
I can only use the provided 2 meter cable.  Being USB,  I expected to be
able to
put any 5 meter cable on it.  I hate surprises like that, don't you?

We have tested dozens of different USB cables, looking for a solution to the
Immunity Problems we are encountering (Even the Gold Plated 12MB/s versions
which tested no better than the cheep ones). We discovered that we could get
it
to pass Immunity if the impedance of the USB cable was improved.  We would
simulate this by going over a standard USB cable with a better, heavier
braided
shield and then soldering the shield to the backshells (connecting a ground
strap between the instrument and the computer would often give similar
results).
The problem with this approach is that no one makes a cable like this. I
understand that USB cables are constructed according to the USB standard
which
includes a DC cable shield impedance requirement which in my opinion should
be
lower and include impedance requirements for the entire frequency band.  

So, to all you USB Experts out there, please education me in the finer
points of
USB.

1. Does the USB specification take into account any Immunity Requirements?
If
so, to what levels?

2. Any recommendations to improve a USB systems performance during Immunity
Testing?

3. What are others doing?  I expect that they are testing with short USB
cables
then specifying (or not) the length in the user's manual.  

4. What changes can we expect to see in the future of USB? We know the
interface
is getting faster and faster.  Is functionality, cable length, Emissions,
and
Immunity being considered?  



Brian Kunde
LECO Corp.



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Medical equipment and EN61000-3-2

[plawler]

The scope of EN61000-3-2:2001 says that the standard deals with harmonic
currents injected into the public low-voltage distribution system.

I can see that residences and offices are connected to the public system.
However, I don't know about distribution to hospitals.

Are their power requirements specialized enough that their electricity is
provided by a MV transformer?  This would exempt hospital-only medical products
from the harmonic current requirements.
Or are their different levels of hospitals, some fed by LV transformers, some
fed by MV transformers?

Patrick Lawler
plaw...@west.net

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USB Immunity Specs??

[brian_kunde]

Dear Group,

Our Engineering Department thinks that USB is the worlds best interface.  Though
it has a lot going for it, I'm not sure if is all that, but never the less, I'm
seeing it used to control and interface with commercial and industrial
instrumentation requiring the more severe immunity testing for Europe; e.g.
10volt/meter Radiated Immunity, 10Vrms Conducted Immunity, and 2KV Fast
Transient Testing (1KV using Clamp).

To these higher levels, we have failed almost every USB system we have ever
encountered using USB cables longer than 2 meter in length.  I understand that
USB is suppose to be able to goto 5 meter.  The failure shows itself as a
communication error that usually requires resetting the hardware.

Fairly recently we evaluated one of those "USB Hubs".  Someone realized that if
you run a 5 meter USB cable into a HUB you can run it out another 5 meters.  Our
Immunity testing failed the HUB configuration in the most miserable ways.  A
detailed examination of the manual that came with the USB Hub proudly displayed
a DOC and the CE marking, but gave no special conditions or mention of cable
lengths.

At home I  have a USB Flatbed scanner that came with a 2 meter USB cable with
ferrite beads on BOTH ends.  What might I expect if I went to Best Buy and
bought a 5 meter USB cable and installed it on my scanner?  I guess I would
expect it NOT to comply with emissions requirements, who knows about immunity,
but would it even function?  In any case, I don't think it is right that I can
purchase a scanner and only when I get it home and open the box I find out that
I can only use the provided 2 meter cable.  Being USB,  I expected to be able to
put any 5 meter cable on it.  I hate surprises like that, don't you?

We have tested dozens of different USB cables, looking for a solution to the
Immunity Problems we are encountering (Even the Gold Plated 12MB/s versions
which tested no better than the cheep ones). We discovered that we could get it
to pass Immunity if the impedance of the USB cable was improved.  We would
simulate this by going over a standard USB cable with a better, heavier braided
shield and then soldering the shield to the backshells (connecting a ground
strap between the instrument and the computer would often give similar results).
The problem with this approach is that no one makes a cable like this. I
understand that USB cables are constructed according to the USB standard which
includes a DC cable shield impedance requirement which in my opinion should be
lower and include impedance requirements for the entire frequency band.  

So, to all you USB Experts out there, please education me in the finer points of
USB.

1. Does the USB specification take into account any Immunity Requirements?  If
so, to what levels?

2. Any recommendations to improve a USB systems performance during Immunity
Testing?

3. What are others doing?  I expect that they are testing with short USB cables
then specifying (or not) the length in the user's manual.  

4. What changes can we expect to see in the future of USB? We know the interface
is getting faster and faster.  Is functionality, cable length, Emissions, and
Immunity being considered?  



Brian Kunde
LECO Corp.



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RE: Current from Car 12V cigarette lighter socket

[Jim Eichner]

UL2089 covers appliance using the socket.  There is no UL or CSA standard
covering the socket itself, but there is SAE J563, which provided dimensions
and limits the continuous current drawn through lighter sockets by
appliances to 8Adc.  

The intent is to protect the wiring in behind the lighter socket, because
that wiring is based on an intermittent 10-15A load (how often do you light
a cigarette?) and is therefore undersized for its overcurrent protection.
In a sample of 7 or 8 cigarette lighter sockets and wiring harnesses that I
pulled out of different makes of car in the mid 90's, I found wire sizes
ranging from No. 16AWG to 22AWG, being protected by fuses ranging from 15 to
30A!  

In the world of continuous 12Vdc loads - aftermarket accessories like
chargers for cell phones and laptops, in-your-car coffee makers and vacuum
cleaners, etc - we need to know what continuous load the lighter socket and
its harness can sustain.  The SAE pegs this at 8A and UL and CSA are
enforcing that limit, both in what they will allow a 12Vdc appliance to
draw, and in requiring a max. 8A fuse in the lighter plug.

Recognizing the limitations on lighter sockets, the automotive industry has
come up with the "power point": a cylindrical connector based on the
cigarette lighter socket but designed, fused, wired, and rated for
continuous loads and lacking the bimetal fingers that release the lighter
plug when it's hot.  These are usually rated for 15-20Adc continuous,
allowing designers to be free of the 8A limit. In theory. 

However, since the male plugs on 12Vdc automotive appliances will fit both
the true lighter socket and these newer power points, UL and CSA will not
back down (nor should they) from the 8A limit for a 12Vdc appliance equipped
with a male plug that fits a lighter socket.  They also will not accept a
marking such as "Use only with power points, not with lighter sockets"
because too many cars only have lighter sockets.

Not sure you're trying to do anything with that kind of power level, but you
should be aware of the limitations.

Regards,

Jim Eichner, P.Eng. 
Manager, Engineering Services 
Xantrex Technology Inc. 
e-mail: jim.eich...@xantrex.com 
web: www.xantrex.com 
Any opinions expressed are those of my invisible friend, who really exists.
Honest.  No really.

Confidentiality Notice: This email message, including any attachments, is
for the sole use of the intended recipient(s) and may contain confidential
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-Original Message-
From: Ron Baugh [mailto:ron...@verifone.com]
Sent: Wednesday, September 18, 2002 3:41 AM
To: 'Charles Blackham'; 'emc-p...@majordomo.ieee.org'
Subject: RE: Current from Car 12V cigarette lighter socket



Yes Charles it's UL 2089 "Vehicle Battery Adapters."  I also have a unit
(ITE
Listed) that will operate from a auto battery and I have to make sure that
all
my 12V devices meets this standard.

Ron Baugh
VeriFone, Inc.
-Original Message-
From:   Charles Blackham [SMTP:cblac...@airspan.com]
Sent:   Wednesday, September 18, 2002 2:07 AM
To: 'emc-p...@majordomo.ieee.org'
Subject:Current from Car 12V cigarette lighter socket


Some of our equipment runs off 12Vdc. Typically this is provided by
a UL
Listed ac/dc power supply that meets the Limited Power Source requirement of
IEC60950. We wish to be able to power this from the 12V "cigarette lighter"
socket in a car:

Is there a standard that covers the output of 12V sockets in cars?
Do
they have to meet something similar to the Limited Power Source requirements
of
IEC60950?

regards 

Charlie Blackham 
Senior Approvals Engineer 
Airspan Communications Ltd. 


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EMI from 30 to 100mhz

[Bob Patel]

Hi! I have a fast ethernet design that does not pass
EMI from 30 to 100mhz and based on the scan it is
common mode noise. In my design i have the phy
connected to xfmr1--choke1---connector---I/O
card---xfmr2choke2---rj21---cables---patch
panel---rj45.
Now, if I use shielded cables from RJ21 to patch panel
then I pass with lowest margin of 2db at 66mhz but
want to pass with unshielded cables.
Now, grounding scheme, our chasis has mesh ground
scheme so we isolated the gnd from secondary of xfmr1
and this gnd is same upto the rj21 on i/o card. Xfmr2,
choke2 and RJ21 is on I/O card.
Since the differential mode currents are not
cancelling out they give rise to common mode current
which need path to gnd and since this gnd extends to
RJ21 the I/o cables radiate. Because if we remove the
patch panel and RJ21 then we are OK. Hence I was
thinking to isolate the GND from motherboard and I/O
card i.e. the gnd on I/O card should be connected to
chassis gnd and the gnd on motherboard from secondary
of xfmr1 to connector should be connected to DGND
through a choke.
Any ideas or suggestions with this approach.
Any feedback will be appreciated.
Thanks
Bob

__
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RE: Distributors of Medical Devices in Europe

[Mark Schmidt]

Hi Neil,
Thanks for your response. Let me see if I can clarify. The product we are 
talking about is Class 1 device. We have offices and service centers in the UK, 
Germany and France. In addition to this we use a network of distributors. These 
distributors for this device in question are medical device distributors. 
Currently we manufacture product here in the US but that could change in the 
future. To date we have product that fall into ITE, Laboratory equipment and 
Medical categories. We currently have DOC for this device in question and it 
conforms with the MDD. According to Article 14, COUNCIL DIRECTIVE 93/42/EEC it 
indicates informing the competent authorities in that member state. Thus my 
confusion, I did not concern myself with this issue until recently, when the 
question was asked, "Are there any requirements for European Distributors of 
Medical Devices" . 
Article 14
Article 14
Registration of persons responsible for placing devices on the market
1. Any manufacturer who, under his own name, places devices on the market in 
accordance with the procedures referred to in Article 11 (5) and (6) and any 
other natural or legal person engaged in the activities referred to in Article 
12 shall inform the competent authorities of the Member State in which he has 
his registered place of business of the address of the registered place of 
business and the description of the devices concerned.
2. Where a manufacturer who places devices referred to in paragraph 1 on the 
market under his own name does not have a registered place of business in a 
Member State, he shall designate the person(s) responsible for marketing them 
who is (are) established in the Community. These persons shall inform the 
competent authorities of the Member State in which they have their registered 
place of business of the address of the registered place of business and the 
category of devices concerned.
3. The Member States shall on request inform the other Member States and the 
Commission of the details referred to in paragraphs 1 and 2.
Thank you,

Mark Schmidt
Regulatory Compliance 
X-Rite Incorporated 
Grandville, MI 
USA
(616) 257 2469
mschm...@xrite.com



 -Original Message-
From:   Barker, Neil [mailto:neil.bar...@e2vtechnologies.com] 
Sent:   Wednesday, September 18, 2002 11:29 AM
To: Mark Schmidt; emc-p...@majordomo.ieee.org
Subject:RE: Distributors of Medical Devices in Europe

 << File: Neil R. Barker (E-mail).vcf >> In general a Class 1 Medical Device 
requires only a manufacturer's
Declaration of Conformity before it is placed on the market.  However, in
the context of the Medical Devices Directive the manufacturer is not the
person or entity who makes the product but the person or entity who places
the product on the EU market in their own name. Hence a manufacturer can be
one person in an office who contracts with others to design and manufacture
a product which is then placed on the market under a label, "Brand X", that
belongs to the one-person company. It is the responsibility of that
one-person company to issue the Declaration of Conformity, and it is their
responsibility to ensure that all the requirements of the MDD are met.
In the case of Distributors, it is the responsibility of the original
importer into the EU, but not of further distibution thereafter. It is worth
reading the Directive itself. It is not that large a document and is quite
readable.

Best regards,

Neil R. Barker
Compliance Engineering Manager
E2V Technologies
Waterhouse Lane
Chelmsford
Essex
CM1 2QU
U.K.

Tel: +44 (01245) 453616
Fax: +44 (01245) 453410
E-mail: neil.bar...@e2vtechnologies.com


> -Original Message-
> From: Mark Schmidt [mailto:mschm...@xrite.com]
> Sent: 18 September 2002 13:11
> To: emc-p...@majordomo.ieee.org
> Subject: Distributors of Medical Devices in Europe
> 
> 
> 
> Hello Group,
> 
> Are there any requirements for European Distributors of 
> Medical Devices, i.e. license or registration. The Device in 
> question is a Class 1 device.
> 
> Thank you.
> 
> Mark Schmidt
> Regulatory Compliance 
> X-Rite Incorporated 
> Grandville, MI 
> USA
> (616) 257 2469
> mschm...@xrite.com
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
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> 

 

RE: Question: Discharge capacitance 0.1 uF

[Grasso, Charles]

Hi All,

 

>From personal experience I can tell you that the involuntary reaction to a
shock can have serious consequences to
the sales of a company. In a former life - a previous employer OEM'd a PC
from a Korean Company. The PC had all
the relevant marks but somehow the resistor that was supposed to bleed off
the caps didn't make it into 
production. A customer , moving said model from one location to another,
touched the mains terminals and felt a shock.
The customer fell over, the PC landed on the customer, the customer sued and
the story ended up in the papers.
The sales of PCs essentially died after that. - All for the sake of one
resistor.

 

Best Regards
Charles Grasso
Senior Compliance Engineer
Echostar Communications Corp.
Tel:  303-706-5467
Fax: 303-799-6222
Cell: 303-204-2974
Email: charles.gra...@echostar.com;    
Email Alternate: chasgra...@ieee.org  

 

-Original Message-
From: John Allen [mailto:john.al...@era.co.uk] 
Sent: Wednesday, September 18, 2002 11:11 AM
To: emc-p...@majordomo.ieee.org
Subject: Question: Discharge capacitance 0.1 uF

 

Hello Folks

Tomonori Sato  commented "However, I think discharge from 0.1uF capacitor
charged to the mains peak voltage can be quite uncomfortable."

I believe that to be true from personal experience and from having to
investigate the results of a number of such incidents, and so would remind
member of a point that I made several years ago on this forum: 

The primary shock almost certainly will NOT hurt a person, but the
involuntary reaction TO the shock may well have much more
seriousconsequences. 

This type of shock is often encountered by people who pick up equipment
which they have just unplugged from the AC mains in order to carry it
elsewhere.  If they then touch the pins of the plug there are numerous
reported incidences of them involuntarily dropping the unit - and that can
possibly be on their own feet - and from a height of about 3ft/1m! If the
unit is more than a couple of pounds (about one kilo) then the injury to t!
he feet can be substantial. 

Worse situations could occur in industrial equipment when a service engineer
opens a cabinet to perform a service operation - the reaction from the
"shock" could cause him to strike touch other hazardous electrical or
mechanical parts (which probably should also not be there, I do agree!)
which then cause him serious actual injury.

These types of incident do not make the equipment supplier very "popular" to
say the least, and could result in product liability claims.

The main basis for the claims would be that the supplier had not adequately
assessed the hazards and taken the appropriate simple precautions which are
easily and cheaply available - fit a bleeder resistor across the capacitor,
or use a filter with a resistor already built in (or with
transformer/inductor windings directly across the capacitor - which achieve
the same result) !

Again from personal experience I can say that it is a very "embarassing" and
un! comfortable experience to have to write to an injured or anno! yed
person, or to his employer, to say "sorry, but that is what the safety
standard allows". It is just not good "business sense".

Therefore, regardless of the requirements of the various standards and this
argument over capacitor value and/or charging voltage, I firmly believe that
the use of bleeder resistors should be considered effectively mandatory, and
have always recommended it to engineers I have advised on product safety.

Regards

John Allen
Technical Consultant
Electromagnetics, Safety and Reliability Group
ERA Technology Ltd
Cleeve Rd
Leatherhead
Surrey KT22 7SA
Tel:  +44 (0) 1372-367025 (Direct)
+44 (0) 1372-367000 (Switchboard)
Fax:  +44 (0) 1372-367102 (Fax)

--
Replies to this message may be posted in the following public forum:
Question: 
Discharge capacitance 0.1 uF 

RE: DSL Modems

[Clement Dave-LDC009]

Dan,

I just got DSL service from Verizon in Mass and the second senerio is what I 
got. They sent me a self install kit which didn't require anyone from Verizon 
to come to the house for the installation. I just waited until I got a message 
from them that my line was tied into the DSLAM at the CO and I followed the 
installation instructions. When I ordered the service I just told them how many 
jacks in the house and how many of them were wall phones and they sent an 
appropriate number of filters.

Your original hook up would have required Verizon to do the hook up and unless 
I missed something would have resulted in a dedicated line from the wall to the 
DSL modem. The way they do it now would allow any jack in the house to be used.

Dave Clement
Motorola Inc.
Test Lab Services
Homologation Engineering
20 Cabot Blvd.
Mansfield, MA 02048

P:508-851-8259
F:508-851-8512
C:508-725-9689
mailto:dave.clem...@motorola.com
http://www.motorola.com/globalcompliance/




-Original Message-
From: Roman, Dan [mailto:dan.ro...@intel.com]
Sent: Wednesday, September 18, 2002 8:56 AM
To: 'Peter Merguerian'; 'Rob Keller'; emc-p...@majordomo.ieee.org
Subject: RE: DSL Modems



All,

When Verizon installed my ADSL service a couple years back they put in what
they called a whole house filter, but it is actually a splitter/filter.  I
don't recall any Listing marks of any kind on the device.  It was installed
on the network side of the gray box on the side of my house, not on the
customer premise side so Listing may not apply.  I took the device with me
when I moved but DSL was not available in my new location.  It is potted so
I have no hope of determining the construction, guess I could apply ring
voltage to it in the lab and hi-pot it and see what happens!  I suspect
though that it is TNV-3 in and TNV-3 out.

Shortly after my DSL was installed (I was one of the first in my area) they
stopped installing the whole house splitter and required the user to put a
filter on every phone (yuk) except for the DSL modem.  So even if splitters
are available that do a TNV-3 to TNV-1 or even TNV-3 to SELV connection, at
least in the Verizon NJ customer area DSL modems are TNV-3 all the time.

Dan

-Original Message-
From: Peter Merguerian [mailto:pmerguer...@itl.co.il]
Sent: Wednesday, September 18, 2002 9:24 AM
To: 'Rob Keller'; emc-p...@majordomo.ieee.org
Subject: RE: DSL Modems



Rob Hi!

I assume that the "ADSL" modem is connected to the phone line through an
external splitter. If you find an approved splitter having the required
TNV-3 to TNV-1 insulation, and you specify the specific splitter in your
manual, I gather that your interface can be TNV-1. If no such splitter is
specified, then the interface should be classified TNV-3.

Now a question to the group - is anyone familiar with external
Listed/Certified splitters that have the TNV-3 - TNV-1 insulation? 


This e-mail message may contain privileged or confidential information. If
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PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175
http://www.itl.co.il
http://www.i-spec.com





-Original Message-
From: Rob Keller [mailto:r...@cclab.com]
Sent: Tuesday, September 17, 2002 10:38 PM
To: emc-p...@majordomo.ieee.org
Subject: DSL Modems



Greetings all,

Question regarding the classification of DSL modems.  DSL modems connect
to the standard telecom network yet they do not require a ring signal or
go on/off hook,  therefore the classification would be TNV-1. Yet there
are ring signals still present on the telecom lines for the the other
equipment.  So, because of the ring signals, which would exceed the
limits of SELV,  connecting to the input the modem, should the
classification be TNV-3.  Any insight would be greatly appreciated.


Rob Keller
Product Safety Engineer
Communication Certification Laboratory
r...@cclab.com


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Breaker panel lockout-tagout

[LCrane]

Group, 

Is anyone aware of an authoritative position on the acceptability (or not)
of applying a lock to a breaker panel cover (and so affecting access to
other, unrelated, breakers behind the same cove) to achieve OSHA compliant
Lockout/Tagout rather than applying the lock to breaker directly?

-Lauren Crane
TUV America

Question: Discharge capacitance 0.1 uF

[John Allen]

Hello Folks

Tomonori Sato  commented "However, I think discharge from 0.1uF capacitor 
charged to the mains peak voltage can be quite uncomfortable."

I believe that to be true from personal experience and from having to 
investigate the results of a number of such incidents, and so would remind 
member of a point that I made several years ago on this forum: 

The primary shock almost certainly will NOT hurt a person, but the involuntary 
reaction TO the shock may well have much more seriousconsequences. 

This type of shock is often encountered by people who pick up equipment which 
they have just unplugged from the AC mains in order to carry it elsewhere.  If 
they then touch the pins of the plug there are numerous reported incidences of 
them involuntarily dropping the unit - and that can possibly be on their own 
feet - and from a height of about 3ft/1m! If the unit is more than a couple of 
pounds (about one kilo) then the injury to the feet can be substantial. 

Worse situations could occur in industrial equipment when a service engineer 
opens a cabinet to perform a service operation - the reaction from the "shock" 
could cause him to strike touch other hazardous electrical or mechanical parts 
(which probably should also not be there, I do agree!) which then cause him 
serious actual injury.

These types of incident do not make the equipment supplier very "popular" to 
say the least, and could result in product liability claims.

The main basis for the claims would be that the supplier had not adequately 
assessed the hazards and taken the appropriate simple precautions which are 
easily and cheaply available - fit a bleeder resistor across the capacitor, or 
use a filter with a resistor already built in (or with transformer/inductor 
windings directly across the capacitor - which achieve the same result) !

Again from personal experience I can say that it is a very "embarassing" and 
uncomfortable experience to have to write to an injured or annoyed person, or 
to his employer, to say "sorry, but that is what the safety standard allows". 
It is just not good "business sense".

Therefore, regardless of the requirements of the various standards and this 
argument over capacitor value and/or charging voltage, I firmly believe that 
the use of bleeder resistors should be considered effectively mandatory, and 
have always recommended it to engineers I have advised on product safety.

Regards

John Allen
Technical Consultant
Electromagnetics, Safety and Reliability Group
ERA Technology Ltd
Cleeve Rd
Leatherhead
Surrey KT22 7SA
Tel:+44 (0) 1372-367025 (Direct)
+44 (0) 1372-367000 (Switchboard)
Fax:+44 (0) 1372-367102 (Fax)



--
Replies to this message may be posted in the following public forum:
Question: Discharge capacitance 0.1 uF 
(http://ieeepstc.mindcruiser.com/direct/topic/a/ID509830)

RE: EN60065 mains switches

[Tyra, John]

Hello Chris,

We are going through the same issue here at Bose...A while back we received
a ruling that this type of design did meet the intent of the standard from
TUV and UL. CSA was a little more stringent in their interpretation.

Based on my correspondence with CSA here is my take:

1. You do not need a switch if your product is switched off automatically
either by a timer function or by an external signal provided your amp
outputs are actually switched off and the product is not simply in standby
mode.
2. Your product must not consume more then 15W when in the off mode (see the
CSA excerpt below) under normal conditions and after a single fault
condition. So if you use a single semiconductor to switch off your amp you
would not meet the intent of the standard if your product draws more than
15W with the semiconductor shorted. This point is also clarified in the
IEC60065 6th CENELEC OSM decisions from 7/2001 in sub-clause 14.6.2. 

Here is a short excerpt concerning IEC60065 sub-clause 14.6.2 I got from CSA
on this issue:

"Irrespective of their power consumption" means power consumption in the
ON mode. If there is no manual OFF switch, it is permitted to have the
product switched OFF automatically using a signal.
"Mute" is not really OFF, but a STANDBY mode.   The intent of the standard
is reduce fire hazard by disconnecting the supply voltage from the circuitry
in the OFF mode.   "Mute" with Supply Voltage still connected to the output
stage does not really satisfy this intent.

Some other designs have used electronic switching of the MAINS or Secondary
Supply to satisfy the OFF condition. Even if AUTOMATICALLY SWITCHED, the
second paragraph of 14.6.2 applies to the OFF condition.(Less than 15W with
single fault)

Contact me if you want a copy of the OSM decisions. Please note that these
decisions are only guidelines which were agreed upon by the various CENELC
member Notified Bodies and do not legally change the Standard. I have no
verification that these decisions would be accepted outside the EU, i.e. in
Asia...etc...

Also be aware that the published 7th edition of IEC60065 eliminates the need
for a switch which is in line with the current edition of UL6500.
Unfortunately it will probably be several years before all the countries
adopt this edition of the standard

Hope this helps as this is a tricky area to interpret

regards,

John Tyra
Design Assurance Engineering,
Product Safety & Regulatory Manager

Bose Corporation
The Mountain, M.S.-450
Framingham, MA 01701-9168
508-766-1502 Phone
508-766-1145 Fax
john_t...@bose.com 


-Original Message-
From: Colgan, Chris [mailto:chris.col...@tagmclaren.com]
Sent: Wednesday, September 18, 2002 4:48 AM
To: 'Emc-Pstc' (E-mail)
Subject: EN60065 mains switches



Hello

I know that engineers familiar with EN60065 are rarer than hen's teeth but
maybe someone out there can help me...

Clause 14.6.2 allows for no mains switch to be fitted if the product can be
switched on or off or both automatically.  Do you think that an audio
amplifier that utilises an input signal detect circuit to automatically
switch on fulfils the requirements of this clause?

Thanks for any input

Chris Colgan
Compliance Engineer
TAG McLaren Audio Ltd
The Summit, Latham Road
Huntingdon, Cambs, PE29 6ZU
*Tel: +44 (0)1480 415 627
*Fax: +44 (0)1480 52159
* Mailto:chris.col...@tagmclaren.com
* http://www.tagmclaren.com



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contract for the sale and purchase of the products ordered to the
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RE: Acousic Noise from ITE

[richwoods]

Thanks for that update. I forgot to mention that the agency said that EN
27779 (ISO 7779) is the appropriate measurement standard.

Richard Woods
Sensormatic Electronics
Tyco International


-Original Message-
From: Luttrell, Lyle [mailto:lluttr...@peakstor.com]
Sent: Wednesday, September 18, 2002 12:12 PM
To: 'richwo...@tycoint.com'; emc-p...@majordomo.ieee.org
Subject: RE: Acousic Noise from ITE


There is a voluntary standard that has been developed in Sweden by
Statskontoret.  The standard is based on the measurement methods of ISO7779.
The latest version of this standard was issued early this year - link is 
http://www.statskontoret.se/projekt/standardisering/TN26.pdf

Lyle Luttrell, PE
PeAk Storage Solutions, a Division of MaxOptix
246 South Taylor Avenue
Louisville, CO 80027



-Original Message-
From: richwo...@tycoint.com [mailto:richwo...@tycoint.com]
Sent: Wednesday, September 18, 2002 6:26 AM
To: emc-p...@majordomo.ieee.org
Subject: RE: Acousic Noise from ITE



According to a well known German safety agency, there are no normative EU or
German national acoustic limits for ITE. The 3rd GS Ordinance on product
safety includes the requirements of the LVD and Machinery Directive, but the
requirement for acoustic noise is understood to apply only to machinery.
Even then, the requirment is to document the level in the manual, and no
maximum levels are specified. There are German ocupational regulations that
apply to the workplace environment, but those limits are for the work
locations where the noise can originate at many sources.

Does anyone else any input on ITE?

Richard Woods
Sensormatic Electronics
Tyco International

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Immunity severity levels

[alan . hudson]

With regard to radiated emission immunity and EN61000-4-3 (or IEC 801-3)
I believe there are different field strengths used, depending on the
environment in which the apparatus being tested is to be used.

I believe equipment to be used in a well-protected environment may be
tested at a lower immunity level than equipment to be used in an
unprotected environment.

I've ordered a copy of 61000-4-3, but while I'm waiting I'd like to know
ASAP:

1) What are the definitions of the levels?
2) What field strengths  are used for the various levels? (I think level
2 is 3V/m and level 3 is 10V/m)

Regards,

Alan


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Re: CE Marking for Passive speakers

[SOUNDSURFR]

In a message dated 9/18/02 4:40:07 AM Eastern Daylight Time, 
j...@jmwa.demon.co.uk writes:


> >>>Have you looked at a properly-labelled loudspeaker? Or the spec for a
> pair of headphones? Electrical ratings in there!
> 

I own four sets of passive loudspeakers, a passive subwoofer and two pairs of 
headphones.  I don't know which, if any of them are "properly labelled", but 
none of them carry a voltage rating - which is what the scope criteria of the 
LVD considers.  I'm sorry, but I'm ignorant of what EN 60065 says on the 
subject.  Is a voltage rating required on passive loudspeakers?

I cited EN60065 and the EMC Guidelines document.

Which brings up an interesting questioncan we assume that the scope of an 
EN standard is harmonized with the scope of a Directive?   For example, if an 
EN standard includes requirements for a specific product (case in point, 
passive loudspeaker), and the EN standard is listed in an Annex of the LVD, 
is this grounds to conclude that the product is "clearly covered" under the 
LVD?  I believe the answer is no.  

I think we should be careful to remember that it is the Directive that 
establishes the legal scope of CE marking application and the EN standard is 
a voluntary instrument that can be used to establish compliance at the 
manufacturer's discretion.




Greg G.
www.producapprovals.com

RE: Acousic Noise from ITE

[Luttrell, Lyle]

There is a voluntary standard that has been developed in Sweden by
Statskontoret.  The standard is based on the measurement methods of ISO7779.
The latest version of this standard was issued early this year - link is 
http://www.statskontoret.se/projekt/standardisering/TN26.pdf

Lyle Luttrell, PE
PeAk Storage Solutions, a Division of MaxOptix
246 South Taylor Avenue
Louisville, CO 80027



-Original Message-
From: richwo...@tycoint.com [mailto:richwo...@tycoint.com]
Sent: Wednesday, September 18, 2002 6:26 AM
To: emc-p...@majordomo.ieee.org
Subject: RE: Acousic Noise from ITE



According to a well known German safety agency, there are no normative EU or
German national acoustic limits for ITE. The 3rd GS Ordinance on product
safety includes the requirements of the LVD and Machinery Directive, but the
requirement for acoustic noise is understood to apply only to machinery.
Even then, the requirment is to document the level in the manual, and no
maximum levels are specified. There are German ocupational regulations that
apply to the workplace environment, but those limits are for the work
locations where the noise can originate at many sources.

Does anyone else any input on ITE?

Richard Woods
Sensormatic Electronics
Tyco International

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RE: CE Marking for Passive speakers

[Garry Hojan]

I would have to agree with you Greg. When it isn't clear, step back, ask
what would be considered "due diligence" if marking ever came into question.
Look to what your industry is doing as a whole. If a there is a precedence
for marking, it might be a good idea to find out why and follow suit.

Garry
www.regulatory-compliance.com

-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of
soundsu...@aol.com
Sent: Wednesday, September 18, 2002 5:28 AM
To: emc-p...@majordomo.ieee.org
Subject: Re: CE Marking for Passive speakers



So to recap, so far we've got:

a.  Yes, they're clearly covered under both the EMC and LVD Directives.
b.   No, they're not necessarily covered under either Directive.
c.   There's no testing required to CE Mark passive speakers.
d.   Passive speakers could be affected by radiated emmissions and therefore
should be tested for immunity.

In other words, a classic New Approach Directive discussion.

I think John Tyra's original quest for an EC ruling on the subject is
entirely understandable.  I would caution, however, that after a lot of time
and effort, he may receive such a ruling and find it to be even more
confusing.

In the end, it seems the decision is left to the manufacturer and the market
forces that be.   Just my opinion.



Greg
www.productapprovals.com


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Re: CE Marking for Passive speakers

[John Woodgate]

I read in !emc-pstc that Gordon,Ian  wrote
(in ) about 'CE
Marking for Passive speakers' on Wed, 18 Sep 2002:
>Thus whilst I agree with your view on loudspeakers, I don't concur with your
>view of the wider issue.

What 'wider issue'? The discussion was about loudspeakers and
headphones. I'm not suggesting that digital watches should be CE-marked.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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Re: Clock frequencies

[Joe P Martin]

Neil,

Section 15.33  of FCC Part 15 "Frequency Range of Radiated Measurements"
provides you with this information.

Regards

Joe Martin
Applied Biosystems




  
Neil Helsby 
  
cc:  
  
Sent by:   Subject: Clock 
frequencies 
owner-emc-pstc@majordom 
  
o.ieee.org  
  

  

  
09/18/2002 03:53 AM 
  
Please respond to Neil  
  
Helsby  
  

  

  





I read somewhere, and now cannot find, a reference to FCC requirements
with respect to the relationship between clock frequency and highest
emissions scan frequency.

Can anyone help, preferably pointing to the FCC document?

I also seem to remember similar comments being considered by the EU. Can
anyone advise on these?

Many thanks,

Neil Helsby


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RE: DSL Modems

[David Heald]

I remember working on such a filter a few years ago and from what I remember
there were no isolation type components - it was more of a high pass/low
pass filter rather than an isolation type device.  This is just my memory
though, so I could be wrong.  

If you think about it though, there is really not much need for an isolation
type device within such a filter (& it would add cost) ...and the loss from
an isolation component would further effect the already critical distance
requirements for DSL, so I doubt that these filters would have an isolation
component. 

Dave

-Original Message-
From: Roman, Dan [mailto:dan.ro...@intel.com]
Sent: Wednesday, September 18, 2002 8:56 AM
To: 'Peter Merguerian'; 'Rob Keller'; emc-p...@majordomo.ieee.org
Subject: RE: DSL Modems



All,

When Verizon installed my ADSL service a couple years back they put in what
they called a whole house filter, but it is actually a splitter/filter.  I
don't recall any Listing marks of any kind on the device.  It was installed
on the network side of the gray box on the side of my house, not on the
customer premise side so Listing may not apply.  I took the device with me
when I moved but DSL was not available in my new location.  It is potted so
I have no hope of determining the construction, guess I could apply ring
voltage to it in the lab and hi-pot it and see what happens!  I suspect
though that it is TNV-3 in and TNV-3 out.

Shortly after my DSL was installed (I was one of the first in my area) they
stopped installing the whole house splitter and required the user to put a
filter on every phone (yuk) except for the DSL modem.  So even if splitters
are available that do a TNV-3 to TNV-1 or even TNV-3 to SELV connection, at
least in the Verizon NJ customer area DSL modems are TNV-3 all the time.

Dan

-Original Message-
From: Peter Merguerian [mailto:pmerguer...@itl.co.il]
Sent: Wednesday, September 18, 2002 9:24 AM
To: 'Rob Keller'; emc-p...@majordomo.ieee.org
Subject: RE: DSL Modems



Rob Hi!

I assume that the "ADSL" modem is connected to the phone line through an
external splitter. If you find an approved splitter having the required
TNV-3 to TNV-1 insulation, and you specify the specific splitter in your
manual, I gather that your interface can be TNV-1. If no such splitter is
specified, then the interface should be classified TNV-3.

Now a question to the group - is anyone familiar with external
Listed/Certified splitters that have the TNV-3 - TNV-1 insulation? 


This e-mail message may contain privileged or confidential information. If
you are not the intended recipient, you may not disclose, use, disseminate,
distribute, copy or rely upon this message or attachment in any way. If you
received this e-mail message in error, please return by forwarding the
message and its attachments to the sender.




PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175
http://www.itl.co.il
http://www.i-spec.com





-Original Message-
From: Rob Keller [mailto:r...@cclab.com]
Sent: Tuesday, September 17, 2002 10:38 PM
To: emc-p...@majordomo.ieee.org
Subject: DSL Modems



Greetings all,

Question regarding the classification of DSL modems.  DSL modems connect
to the standard telecom network yet they do not require a ring signal or
go on/off hook,  therefore the classification would be TNV-1. Yet there
are ring signals still present on the telecom lines for the the other
equipment.  So, because of the ring signals, which would exceed the
limits of SELV,  connecting to the input the modem, should the
classification be TNV-3.  Any insight would be greatly appreciated.


Rob Keller
Product Safety Engineer
Communication Certification Laboratory
r...@cclab.com


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RE: Question: Discharge capacitance 0.1 uF

[T.Sato]

On Wed, 18 Sep 2002 13:11:23 +0100,
  "Barker, Neil"  wrote:

> The answer to this one is simply that for capacitances up to 0.1 uF, and for
> voltages up to the maximum mains supply voltage covered by the standard, the
> stored energy is sufficiently low as to be considered not hazardous. Above

Is it true even if the mains voltage is 600V rms, i.e. if the
0.1uF capacitor can be charged around 850V?

I think it should be thought as Hazardous Voltage and should not
accessible by the operator - am I overlooking something?

Regards,
Tom

--
Tomonori Sato  
URL: http://member.nifty.ne.jp/tsato/

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RE: Clock frequencies

[Pettit, Ghery]

Neil,

Work is progressing in CISPR SC I to generate limits above 1 GHz for CISPR
22.  This would be a requirement in more than just the EU.  There is much
disagreement as to what the limits should be.  The latest proposal that was
out for comments used the FCC limits up to 18 GHz, but with a modified test
procedure.  Comments from a number of European countries claim that these
limits are not strict enough and some are pushing for limits about 6 dB
lower than the FCC limits.

CISPR SC I meets next week in Christchurch, New Zealand and this will be a
topic of discussion at the meetings.  We on the US delegation will be trying
to keep the voices for tighter limits from being successful.  These limits
have been an issue for a number of years and progress is SLOW.  For now,
test above 1 GHz for the US and you are covered for the rest of the world as
we are the only country with limits there.

Ghery Pettit
Intel
Member, USNC IEC / CISPR SCI TAG


-Original Message-
From: Neil Helsby [mailto:nei...@solid-state-logic.com]
Sent: Wednesday, September 18, 2002 3:54 AM
To: emc-p...@majordomo.ieee.org
Subject: Clock frequencies



I read somewhere, and now cannot find, a reference to FCC requirements 
with respect to the relationship between clock frequency and highest 
emissions scan frequency. 

Can anyone help, preferably pointing to the FCC document?

I also seem to remember similar comments being considered by the EU. Can 
anyone advise on these?

Many thanks,

Neil Helsby


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Looking for good USB EMI suppression techniques

[Dan Pierce]

Greetings:

I am looking for a good design practice regarding USB transmission lines.  I
commonly have problems with 120.00MHz and 252.00MHz. 

Thanks in advance.

Daniel J. Pierce
Sr. Design Engineer
OpenGlobe, Inc.
> (An Escient Technologies Affiliate)
6325 Digital Way
Indianapolis, IN  46278

mailto:dpie...@openglobe.net
 
P:  (317) 616.6587
F:  (317) 616.6587

<>

RE: Clock frequencies

[Gary McInturff]

Section 15.33
(b) For unintentional radiators:
(1) Except as otherwise indicated in paragraphs (b)(2) or (b)(3), for an 
unintentional
radiator, including a digital device, the spectrum shall be investigated from 
the lowest radio frequency
signal generated or used in the device, without going below the lowest 
frequency for which a radiated
emission limit is specified, up to the frequency shown in the following table:
Highest frequency generated or Upper frequency of measurement
used in the device or on which the range (MHz)device operates or tunes (MHz)
_
Below 1.705 30
1.705 - 108 1000
108 - 500 2000
500 - 1000 5000
Above 1000 5th harmonic of the highest frequency or
40 GHz, whichever is lower
_
(2) A unintentional radiator, excluding a digital device, in which the highest 
frequency
generated in the device, the highest frequency used in the device and the 
highest frequency on which the
device operates or tunes are less than 30 MHz and which, in accordance with 
Section 15.109, is required
to comply with standards on the level of radiated emissions within the 
frequency range 9 kHz to 30 MHz,
such as a CB receiver or a device designed to conduct its radio frequency 
emissions via connecting wires
or cables, e.g., a carrier current system not intended to radiate, shall be 
investigated from the lowest radio
frequency generated or used in the device, without going below 9 kHz (25 MHz 
for CB receivers), up to
the frequency shown in the following table. If the unintentional radiator 
contains a digital device, the upper
frequency to be investigated shall be that shown in the table below or in the 
table in paragraph (b)(1)
above, as based on both the highest frequency generated and the highest 
frequency used in the digital
device, whichever range is higher.
Highest frequency generated or Upper frequency of measurement
used in the device or on which the range (MHz)
device operates or tunes (MHz)
_
Below 1.705 30
1.705 - 10 400
10 - 30 500
_













-Original Message-
From: Neil Helsby [mailto:nei...@solid-state-logic.com]
Sent: Wednesday, September 18, 2002 3:54 AM
To: emc-p...@majordomo.ieee.org
Subject: Clock frequencies



I read somewhere, and now cannot find, a reference to FCC requirements 
with respect to the relationship between clock frequency and highest 
emissions scan frequency. 

Can anyone help, preferably pointing to the FCC document?

I also seem to remember similar comments being considered by the EU. Can 
anyone advise on these?

Many thanks,

Neil Helsby


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Spectrum analyzer problem, noise

[Jochen Feldhaar]

Hi all,

I operate a spectrum analyzer model HP 853A with a 8558B RF unit, which
has a strange problem around the first LO, a YIG oscillator. As some of
you will use these also, I think it is OK to ask this question.

When switching on the unit, the noise floor on the screen is 20 dB above
the usual value, from 0 thru 700 MHz, then declining to normal at 900
MHz and higher. The effect will vanish if I tune to a CF of 1100 MHz or
higher. It will appear only if the unit has been in daily use for my
usual 8-10 hours, for several weeks continuously. Some months ago, I did
a lot of paperwork (and my vacation!) and didn't use it, the effect was
gone during the following several weeks of heavy usage, only to appear
again after some time.

I would like to know if anyone can give me a tip as to the particaular
cause of this failure mode, or perhaps point me in a direction where I
could start to dig for a new component.
Is it indeed the YIG osc, is it the first mixer or some circuitry around
this assembly (e. g. heater, driver, voltages)?

Thanks,

Jochen  Feldhaar DH6FAZ
Telejet GmbH

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RE: DSL Modems

[Clement Dave-LDC009]

The ADSL modem connects directly to the phone line. The filters go on the rest 
of your phones in the house to block any interference in the voice band. The 
ones I have seen would be considered TNV-3 on both sides. But they would at 
least need to be TNV-2 on the phone side because you would still need to pass 
the ring signals.

I have done safety and telecom approvals on a couple of ADSL modems and the 
port was treated as TNV-3. The SDSL and IDSL modems I have done approvals on, 
the port was treated as TNV-1.

I just got ADSL service for my house. The modem and all the filters were UL 
listed as well as Part 68 approved.

FWIW, if you had a splitter that had a TNV-3 barrier in it the other side would 
be either SELV or TNV-2 not TNV-1. However, the splitters I have seen have no 
barrier and are TNV-3 on both sides.

Dave Clement
Motorola Inc.
Test Lab Services
Homologation Engineering
20 Cabot Blvd.
Mansfield, MA 02048

P:508-851-8259
F:508-851-8512
C:508-725-9689
mailto:dave.clem...@motorola.com
http://www.motorola.com/globalcompliance/


-Original Message-
From: Peter Merguerian [mailto:pmerguer...@itl.co.il]
Sent: Wednesday, September 18, 2002 9:24 AM
To: 'Rob Keller'; emc-p...@majordomo.ieee.org
Subject: RE: DSL Modems



Rob Hi!

I assume that the "ADSL" modem is connected to the phone line through an
external splitter. If you find an approved splitter having the required
TNV-3 to TNV-1 insulation, and you specify the specific splitter in your
manual, I gather that your interface can be TNV-1. If no such splitter is
specified, then the interface should be classified TNV-3.

Now a question to the group - is anyone familiar with external
Listed/Certified splitters that have the TNV-3 - TNV-1 insulation? 


This e-mail message may contain privileged or confidential information. If
you are not the intended recipient, you may not disclose, use, disseminate,
distribute, copy or rely upon this message or attachment in any way. If you
received this e-mail message in error, please return by forwarding the
message and its attachments to the sender.




PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175
http://www.itl.co.il
http://www.i-spec.com





-Original Message-
From: Rob Keller [mailto:r...@cclab.com]
Sent: Tuesday, September 17, 2002 10:38 PM
To: emc-p...@majordomo.ieee.org
Subject: DSL Modems



Greetings all,

Question regarding the classification of DSL modems.  DSL modems connect
to the standard telecom network yet they do not require a ring signal or
go on/off hook,  therefore the classification would be TNV-1. Yet there
are ring signals still present on the telecom lines for the the other
equipment.  So, because of the ring signals, which would exceed the
limits of SELV,  connecting to the input the modem, should the
classification be TNV-3.  Any insight would be greatly appreciated.


Rob Keller
Product Safety Engineer
Communication Certification Laboratory
r...@cclab.com


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RE: DSL Modems

[Roman, Dan]

All,

When Verizon installed my ADSL service a couple years back they put in what
they called a whole house filter, but it is actually a splitter/filter.  I
don't recall any Listing marks of any kind on the device.  It was installed
on the network side of the gray box on the side of my house, not on the
customer premise side so Listing may not apply.  I took the device with me
when I moved but DSL was not available in my new location.  It is potted so
I have no hope of determining the construction, guess I could apply ring
voltage to it in the lab and hi-pot it and see what happens!  I suspect
though that it is TNV-3 in and TNV-3 out.

Shortly after my DSL was installed (I was one of the first in my area) they
stopped installing the whole house splitter and required the user to put a
filter on every phone (yuk) except for the DSL modem.  So even if splitters
are available that do a TNV-3 to TNV-1 or even TNV-3 to SELV connection, at
least in the Verizon NJ customer area DSL modems are TNV-3 all the time.

Dan

-Original Message-
From: Peter Merguerian [mailto:pmerguer...@itl.co.il]
Sent: Wednesday, September 18, 2002 9:24 AM
To: 'Rob Keller'; emc-p...@majordomo.ieee.org
Subject: RE: DSL Modems



Rob Hi!

I assume that the "ADSL" modem is connected to the phone line through an
external splitter. If you find an approved splitter having the required
TNV-3 to TNV-1 insulation, and you specify the specific splitter in your
manual, I gather that your interface can be TNV-1. If no such splitter is
specified, then the interface should be classified TNV-3.

Now a question to the group - is anyone familiar with external
Listed/Certified splitters that have the TNV-3 - TNV-1 insulation? 


This e-mail message may contain privileged or confidential information. If
you are not the intended recipient, you may not disclose, use, disseminate,
distribute, copy or rely upon this message or attachment in any way. If you
received this e-mail message in error, please return by forwarding the
message and its attachments to the sender.




PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175
http://www.itl.co.il
http://www.i-spec.com





-Original Message-
From: Rob Keller [mailto:r...@cclab.com]
Sent: Tuesday, September 17, 2002 10:38 PM
To: emc-p...@majordomo.ieee.org
Subject: DSL Modems



Greetings all,

Question regarding the classification of DSL modems.  DSL modems connect
to the standard telecom network yet they do not require a ring signal or
go on/off hook,  therefore the classification would be TNV-1. Yet there
are ring signals still present on the telecom lines for the the other
equipment.  So, because of the ring signals, which would exceed the
limits of SELV,  connecting to the input the modem, should the
classification be TNV-3.  Any insight would be greatly appreciated.


Rob Keller
Product Safety Engineer
Communication Certification Laboratory
r...@cclab.com


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 Ron Pickard:  

RE: Acousic Noise from ITE

[richwoods]

According to a well known German safety agency, there are no normative EU or
German national acoustic limits for ITE. The 3rd GS Ordinance on product
safety includes the requirements of the LVD and Machinery Directive, but the
requirement for acoustic noise is understood to apply only to machinery.
Even then, the requirment is to document the level in the manual, and no
maximum levels are specified. There are German ocupational regulations that
apply to the workplace environment, but those limits are for the work
locations where the noise can originate at many sources.

Does anyone else any input on ITE?

Richard Woods
Sensormatic Electronics
Tyco International

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RE: Current from Car 12V cigarette lighter socket

[richwoods]

Let's think about this for a moment. The output power from a limited power
source is limited such that there is insufficient energy to start a fire.
However, the purpose of a a cigarette lighter is to start a fire. No, it is
not a limited power source. Can you make it one? Yes, by placing the proper
current limiting device in the plug.
Richard Woods 
Sensormatic Electronics 
Tyco International 

-Original Message-
From: Charles Blackham [mailto:cblac...@airspan.com]
Sent: Wednesday, September 18, 2002 5:07 AM
To: 'emc-p...@majordomo.ieee.org'
Subject: Current from Car 12V cigarette lighter socket




Some of our equipment runs off 12Vdc. Typically this is provided by a UL
Listed ac/dc power supply that meets the Limited Power Source requirement of
IEC60950. We wish to be able to power this from the 12V "cigarette lighter"
socket in a car:

Is there a standard that covers the output of 12V sockets in cars? Do they
have to meet something similar to the Limited Power Source requirements of
IEC60950?

regards 

Charlie Blackham 
Senior Approvals Engineer 
Airspan Communications Ltd. 

RE: DSL Modems

[Peter Merguerian]

Rob Hi!

I assume that the "ADSL" modem is connected to the phone line through an
external splitter. If you find an approved splitter having the required
TNV-3 to TNV-1 insulation, and you specify the specific splitter in your
manual, I gather that your interface can be TNV-1. If no such splitter is
specified, then the interface should be classified TNV-3.

Now a question to the group - is anyone familiar with external
Listed/Certified splitters that have the TNV-3 - TNV-1 insulation? 


This e-mail message may contain privileged or confidential information. If
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PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175
http://www.itl.co.il
http://www.i-spec.com





-Original Message-
From: Rob Keller [mailto:r...@cclab.com]
Sent: Tuesday, September 17, 2002 10:38 PM
To: emc-p...@majordomo.ieee.org
Subject: DSL Modems



Greetings all,

Question regarding the classification of DSL modems.  DSL modems connect
to the standard telecom network yet they do not require a ring signal or
go on/off hook,  therefore the classification would be TNV-1. Yet there
are ring signals still present on the telecom lines for the the other
equipment.  So, because of the ring signals, which would exceed the
limits of SELV,  connecting to the input the modem, should the
classification be TNV-3.  Any insight would be greatly appreciated.


Rob Keller
Product Safety Engineer
Communication Certification Laboratory
r...@cclab.com


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Re: CE Marking for Passive speakers

[SOUNDSURFR]

So to recap, so far we've got:

a.  Yes, they're clearly covered under both the EMC and LVD Directives.
b.   No, they're not necessarily covered under either Directive.
c.   There's no testing required to CE Mark passive speakers.
d.   Passive speakers could be affected by radiated emmissions and therefore 
should be tested for immunity.  

In other words, a classic New Approach Directive discussion.

I think John Tyra's original quest for an EC ruling on the subject is 
entirely understandable.  I would caution, however, that after a lot of time 
and effort, he may receive such a ruling and find it to be even more 
confusing. 

In the end, it seems the decision is left to the manufacturer and the market 
forces that be.   Just my opinion.



Greg 
www.productapprovals.com


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RTTE or LVD for Equipment with E1/Intrabuilding

[Peter Merguerian]

Dear All,

For an equipment where the E1 has been assessed for SELV under EN 60 950 (ie
for intrabuilding use and not subject to overvoltages), does the equipment
fall under the RTTE Directive or can the manufacturer declare compliance to
the LVD and EMC Directives.

If under the RTTE Directive, what telecom standard applies to the E1
interface?

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message and its attachments to the sender.




PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175
http://www.itl.co.il
http://www.i-spec.com





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Re: Clock frequencies

[Scott Douglas]

At 10:53 AM 9/18/02 +, Neil Helsby wrote:

I read somewhere, and now cannot
find, a reference to FCC requirements 
with respect to the relationship between clock frequency and highest

emissions scan frequency. 

Can anyone help, preferably pointing to the FCC document?

I also seem to remember similar comments being considered by the EU. Can

anyone advise on these?

Many thanks,

Neil Helsby

Neil,

I think what you are looking for can be found in Part 15 Subpart B
Section 15.33 for unintentional radiators.

This link is a a path to the index for Part 15 on the FCC web site. Each
section can be downloaded in *.pdf or *.txt format.

http://www.access.gpo.gov/nara/cfr/waisidx_01/47cfr15_01.html

Hope this helps.

Scott Douglas


Senior Compliance Engineer
Narad Networks
515 Groton Road 
Westford, MA 01886
phone:  978 589-1869
dougl...@naradnetworks.com
www.naradnetworks.com





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RE: thermocouple welder

[richwoods]

Perhaps he needs a sign based upon one found in a MIT lab: 
"Do not stare into beam with remaining eye"

Richard Woods
Sensormatic Electronics
Tyco International


-Original Message-
From: Gonzalez, Kenneth P (Rocky) [mailto:kpgon...@ingr.com]
Sent: Tuesday, September 17, 2002 3:20 PM
To: Doug McKean; Emc-Pstc Post
Subject: RE: thermocouple welder



All,
Do not look at the spark without eye protection.

Rocky
  -)-(-

Kenneth P. Gonzalez (Rocky)
Intergraph Solutions Group
Integrated Products Division
170 Graphics Drive
Madison, Alabama, USA 35758
phone (256) 730-2131
fax  (256)730-2424
kpgon...@ingr.com


-Original Message-
From: Doug McKean [mailto:dmck...@corp.auspex.com]
Sent: Tuesday, September 17, 2002 1:59 PM
To: Emc-Pstc Post
Subject: Re: thermocouple welder



Yes.  Get a good beefy DC power supply.  

Attach both leads of the thermocouple to one of the 
outputs PLUS or MINUS.  Doesn't matter. 

Twist together the leads to be welded. 

Get a piece of lead that's used in drafters pencils. 

Attach this piece of lead to the other output of 
the power supply.  

Turn on the power supply. 

LIGHTLY and QUICKLY touch the twisted leads 
of the thermocouple to the lead a few times.  

Welding will commence. 


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Distributors of Medical Devices in Europe

[Mark Schmidt]

Hello Group,

Are there any requirements for European Distributors of Medical Devices, i.e. 
license or registration. The Device in question is a Class 1 device.

Thank you.

Mark Schmidt
Regulatory Compliance 
X-Rite Incorporated 
Grandville, MI 
USA
(616) 257 2469
mschm...@xrite.com


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RE: Medical Wrist Device and Cardiac Pacemakers

[Jim Conrad]

Hi Peter,

I'm not sure what your wrist device does.  Does it have electronics
in it with clock frequencies over 9 kHz?  Does it transmit a EMF?
If the device is within CISPR limits then you should be OK for
pacemakers.  I think they are tested at 100 V/m.  Some pacemakers
have a magnetic switch in them that is activated at 10 gauss.   I
will send you a document describing EMI for pacemakers separately.

Jim

-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Peter
Merguerian
Sent: Tuesday, September 17, 2002 8:21 AM
To: "EMC-PSTC (E-mail)" <
Subject: Medical Wrist Device and Cardiac Pacemakers


Dear All,

For a medical device to be worn on the wrist of a patient, does
anyone know
what additional requirements (if any) should the manufacturer of the
medical
device take in order for the device not to interfere with a cardiac
pacemaker?

My little research on the subject tells me that the cardiac
pacemaker
manufacturer should take all the required measures so that any other
device
nearby (cellular telephones, medical equipment, etc.) does not
interfere
with the pacemaker. Is this correct?


Best Regards

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the
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PETER S. MERGUERIAN
Technical Director
I.T.L. (Product Testing) Ltd.
26 Hacharoshet St., POB 211
Or Yehuda 60251, Israel
Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019
Mobile: + 972-(0)54-838175
http://www.itl.co.il
http://www.i-spec.com





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RE: Current from Car 12V cigarette lighter socket

[Peter Merguerian]

Charles,
 
I assume your equipment is ITE for use in vehicles. Since power at the
socket can be non-limiting, best is to design your equipment to have the
required fire enclosure. Your other option is to provide an approved fused
cigarette lighter cord set with built in fuse which would meet the
requirements for limited power source requirements in IEC 60950.
 
 
Regards
 

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you are not the intended recipient, you may not disclose, use, disseminate,
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message and its attachments to the sender.






PETER S. MERGUERIAN

Technical Director

I.T.L. (Product Testing) Ltd.

26 Hacharoshet St., POB 211

Or Yehuda 60251, Israel

Tel: + 972-(0)3-5339022  Fax: + 972-(0)3-5339019

Mobile: + 972-(0)54-838175

http://www.itl.co.il  

http://www.i-spec.com  



-Original Message-
From: Charles Blackham [mailto:cblac...@airspan.com]
Sent: Wednesday, September 18, 2002 11:07 AM
To: 'emc-p...@majordomo.ieee.org'
Subject: Current from Car 12V cigarette lighter socket




Some of our equipment runs off 12Vdc. Typically this is provided by a UL
Listed ac/dc power supply that meets the Limited Power Source requirement of
IEC60950. We wish to be able to power this from the 12V "cigarette lighter"
socket in a car:

Is there a standard that covers the output of 12V sockets in cars? Do they
have to meet something similar to the Limited Power Source requirements of
IEC60950?

regards 

Charlie Blackham 
Senior Approvals Engineer 
Airspan Communications Ltd. 

Clock frequencies

[Neil Helsby]

I read somewhere, and now cannot find, a reference to FCC requirements 
with respect to the relationship between clock frequency and highest 
emissions scan frequency. 

Can anyone help, preferably pointing to the FCC document?

I also seem to remember similar comments being considered by the EU. Can 
anyone advise on these?

Many thanks,

Neil Helsby


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Re: Question: Discharge capacitance 0.1 uF

[T.Sato]

On Fri, 6 Sep 2002 16:19:52 +0900,
  "Michael Jang"  wrote:

> I have a question for "Discharge of capacitors in the primary circuit'
> (Related to 60950 standard)
> 
> Standard 
> Equipment is considered to comply if any capacitor having a marked or nominal
> capacitance exceeding 0.1 uF and connected to the PRIMARY CIRCUIT has a
> means of discharge resulting in a time constant not exceeding:
> - 1 s for Pluggable equipment type A; and
> - 10 s for Permanently connected equipment and for pluggable equipment type B.
> ---
> 
> Why does not consider up to 0.1 uF?

# maybe too late, but...

I think we can apply the limits for Limited Current Circuit to
capacitors connected to the primary circuit, too, and capacitors
up to 0.1uF are considered there.

A capacitor which:

  - capacitance <= 0.1uF for voltage <= 450V, or
  - stored charge <= 45uC for 450V < voltage <= 15kV, or
  - stored energy <= 350mJ for 15kV < voltage.

will become a Limited Current Circuit (2.4.1).

So, for voltage up to 450V d.c. (i.e. up to 318V a.c.), capacitor
up to 0.1uF will become a Limited Current Circuit, hence the voltage
is not Hazardous Voltage (1.2.8.4) - no additional condition would
be required for the capacitor connected to the primary circuit.

However, capacitor larger than 0.1uF would not comply with the
requirements for Limited Current Circuit, and the voltage could be
thought as Hazardous Voltage.
I think that is why the discharge requirement which, under certain
condition, allow capacitor exceeding 0.1uF connected to the primary
circuit was specified.

Regards,
Tom

--
Tomonori Sato  
URL: http://member.nifty.ne.jp/tsato/

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RE: Current from Car 12V cigarette lighter socket

[Ron Baugh]

Yes Charles it's UL 2089 "Vehicle Battery Adapters."  I also have a unit (ITE
Listed) that will operate from a auto battery and I have to make sure that all
my 12V devices meets this standard.

Ron Baugh
VeriFone, Inc.
-Original Message-
From:   Charles Blackham [SMTP:cblac...@airspan.com]
Sent:   Wednesday, September 18, 2002 2:07 AM
To: 'emc-p...@majordomo.ieee.org'
Subject:Current from Car 12V cigarette lighter socket


Some of our equipment runs off 12Vdc. Typically this is provided by a UL
Listed ac/dc power supply that meets the Limited Power Source requirement of
IEC60950. We wish to be able to power this from the 12V "cigarette lighter"
socket in a car:

Is there a standard that covers the output of 12V sockets in cars? Do
they have to meet something similar to the Limited Power Source requirements of
IEC60950?

regards 

Charlie Blackham 
Senior Approvals Engineer 
Airspan Communications Ltd. 


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RE: CE Marking for Passive speakers

[Gert Gremmen]

Hi John

Although your reasoning sounds valid, it's simply
not accurate. Firts; The guidelines are not LAW

"Guidelines are publicly available, but they are not binding in the sense of
legal acts adopted by the Community. The legally binding provisions are
those transposing the EMC Directive"


The EMC directive (=LAW) speaks about :

"apparatus liable to cause electromagnetic disturbance"

What an we say about the properties of a passive
speaker system:

A speaker is no other then a cable,
when it comes to creating magnetic
fields. A cable is not to be evaluated either
when it comes to EMC. It cannot create interference
by itself when put into service by the end user.
It's the connected equipment (here amplifier)
that determines the EMC properties of the speaker.
That the application demands the applicaton of an
amplifier that WILL create magnetic fields
within the speakers filter is irrelevant.
It will create a EMC problem though for the installation
consisting of amplifier + speaker (if there were requirements
for low frequency H-fields for speakers).
Installations are by the same guideline exempted from
ce marking. So does the speaker.
An assessment need to be made by the owner/installer
of the installation. He also is responsible.

This means that is the speakers are part of an delivered
installation, then they are subject to such an assessment.

If they are sold separately, they are not.

Gert Gremmen ,
ce-test, qualified testing


-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate
Sent: Tuesday, September 17, 2002 11:15 PM
To: emc-p...@majordomo.ieee.org
Subject: Re: CE Marking for Passive speakers



I read in !emc-pstc that Gert Gremmen  wrote (in
) about 'CE Marking
for Passive speakers' on Tue, 17 Sep 2002:

>Officially this type of  "apparatus" does not qualify
>for ce marking due to the reasons you gave.

That is simply not correct. EN 60065 specifies the safety requirements.
The EMC Guidelines document explains that having no active components is
NOT grounds for exemption from the EMC Directive.

While most loudspeakers do not emit anything except constant magnetic
field, some have crossover inductors with open ferrite cores. These emit
audio-frequency magnetic fields which are quite strong enough to disturb
a CRT display significantly. That there are no limits for this is due to
CISPR/E (now CISPR/I) having more important matters to work on.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
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Current from Car 12V cigarette lighter socket

[Charles Blackham]

Some of our equipment runs off 12Vdc. Typically this is provided by a UL
Listed ac/dc power supply that meets the Limited Power Source requirement of
IEC60950. We wish to be able to power this from the 12V "cigarette lighter"
socket in a car:

Is there a standard that covers the output of 12V sockets in cars? Do they
have to meet something similar to the Limited Power Source requirements of
IEC60950?

regards

Charlie Blackham
Senior Approvals Engineer
Airspan Communications Ltd.

EN60065 mains switches

[Colgan, Chris]

Hello

I know that engineers familiar with EN60065 are rarer than hen's teeth but
maybe someone out there can help me...

Clause 14.6.2 allows for no mains switch to be fitted if the product can be
switched on or off or both automatically.  Do you think that an audio
amplifier that utilises an input signal detect circuit to automatically
switch on fulfils the requirements of this clause?

Thanks for any input

Chris Colgan
Compliance Engineer
TAG McLaren Audio Ltd
The Summit, Latham Road
Huntingdon, Cambs, PE29 6ZU
*Tel: +44 (0)1480 415 627
*Fax: +44 (0)1480 52159
* Mailto:chris.col...@tagmclaren.com
* http://www.tagmclaren.com



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the part of TAG McLaren Audio Limited. Any orders placed shall
be subject to acceptance by TAG McLaren Audio Limited on its 
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contract for the sale and purchase of the products ordered to the
exclusion of any other terms and conditions.

TAG McLaren Audio Ltd
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Telephone : 01480 415600 (+44 1480 415600)
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Re: CE Marking for Passive speakers

[John Woodgate]

I read in !emc-pstc that soundsu...@aol.com wrote (in ) about 'CE Marking for Passive speakers' on Tue, 17 Sep
2002:
>John,
>
>You wrote, with regard to passive speakers and headphones:
>
>The absence of active components is irrelevant. The EMC and Low Voltage
>Directives apply. 
>
>
>How is it that the Directives apply to products that do not carry an 
>electrical rating?

Have you looked at a properly-labelled loudspeaker? Or the spec for a
pair of headphones? Electrical ratings in there!
>
>And in response to the question of getting a commission ruling on the issue, 
>you wrote:
>
It's already established. You don't need a 'golden word'.
>
>Where exactly is it established, and by whom?
>
I cited EN60065 and the EMC Guidelines document.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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RE: EMC Chamber Relocation

[Wan Juang Foo]

It is a regular thing that chambers get to be dismantled and reassembled
all the time.  IMHO, it is possible to maintain SE of 100 dB for a
relocated chamber.  The guys who sell you the brand new chamber always
assemble and test the complete chamber in their factory before shipment.
The important thing to note is that: not all chambers are alike.  Each
chamber have their own characteristics.

May have to consider this if it is DIY :
(1) the power supply (power quality) in the new location.  This may be an
issue if the original filters are designed for 240V 50Hz ac;
(2) floor loading, if the chamber is one of those using heavy ferrite
tiles;
(3) the condition of the panels, other than the oblivious issue of
corrosion, there may be possible distortion and even delamination,
especially if the metal panels are laminated to a chipboard (wood) base.
This may be an issue if the new site has very  different levels of humidity
and temperature.

BTW, when you are reassembling the chamber, remember to watch out for
'traces' of masking tape or their (tell tale) melted/dried out and brittle
left-over adhesive on and around those (all important) seams or door
frames.  This is especially true if the chamber had been in storage for an
extended period.

I knew of at least one case when one strip of transparent tape have
(stumble and) baffle a bunch of experienced engineers.  I will leave it to
the original authors to tell their tale.  :-)  Cannot recall if Elya Joffe
wrote this 'war' story in the EMCS Newsletter or somewhere else.  Can
someone help?

Finally, beware of your boss (or can it be someone more sinister) who may
have left a single piece of insulated wire in the air vent!  Obviously to
test your proficiency.
:-)

Just my 2 ¢ worth.  Good luck.

Tim Foo








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RE: CE Marking for Passive speakers

[Gordon,Ian]

John
Obviously loudspeakers could be affected by external magnetic fields - and
thus should be tested using the procedure described in EN 61000-4-8
(immunity to power frequency magnetic fields). Thus CE marking against the
EMC Directive is appropriate. In addition, in some instances the drive
voltages are sufficiently high to bring the devices within the scope of the
Low Voltage Directive - and again CE marking may be appropriate.
However, I have attached a link below to one section of Statutory Instrument
2372 which enforces the EMC Directive within the UK. This clearly states:
"Electromagnetically benign apparatus
17.These Regulations do not apply to apparatus the inherent
qualities of which are such that neither is it liable to cause, nor is its
performance liable to be degraded by, electromagnetic disturbance"

Thus whilst I agree with your view on loudspeakers, I don't concur with your
view of the wider issue.
Does anybody else have any ideas?

Thanks
Ian Gordon
-Original Message-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: 17 September 2002 22:15
To: emc-p...@majordomo.ieee.org
Subject: Re: CE Marking for Passive speakers



I read in !emc-pstc that Gert Gremmen  wrote (in
) about 'CE Marking
for Passive speakers' on Tue, 17 Sep 2002:

>Officially this type of  "apparatus" does not qualify
>for ce marking due to the reasons you gave.

That is simply not correct. EN 60065 specifies the safety requirements.
The EMC Guidelines document explains that having no active components is
NOT grounds for exemption from the EMC Directive.

While most loudspeakers do not emit anything except constant magnetic
field, some have crossover inductors with open ferrite cores. These emit
audio-frequency magnetic fields which are quite strong enough to disturb
a CRT display significantly. That there are no limits for this is due to
CISPR/E (now CISPR/I) having more important matters to work on.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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Re: CE Marking for Passive speakers

[John Woodgate]

I read in !emc-pstc that Gert Gremmen  wrote (in
) about 'CE Marking
for Passive speakers' on Tue, 17 Sep 2002:

>Officially this type of  "apparatus" does not qualify
>for ce marking due to the reasons you gave.

That is simply not correct. EN 60065 specifies the safety requirements.
The EMC Guidelines document explains that having no active components is
NOT grounds for exemption from the EMC Directive.

While most loudspeakers do not emit anything except constant magnetic
field, some have crossover inductors with open ferrite cores. These emit
audio-frequency magnetic fields which are quite strong enough to disturb
a CRT display significantly. That there are no limits for this is due to
CISPR/E (now CISPR/I) having more important matters to work on.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 
Interested in professional sound reinforcement and distribution? Then go to 
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

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Re: New EU regulations - civil aviation

[Ken Javor]

Thank you for posting what I excerpted below.  At the risk of this thread 
flaring up again, I have to state that just because a cable assembly or loom
does not have an over-braid shield or screen does not qualify it as being
"unshielded" or "unscreened".  The ONLY excuse for an over-braid is
extremely high radiated immunity threats, either swept frequency or time
domain (intentional transmissions or EMP), or lightning protection, either
direct or indirect.  It IS common practice to individually shield signals
which require it, either to contain emissions and/or protect it from
cross-talk or intentional transmissions.  As I pointed out with a numerical
example in an earlier response, an individual shield provides more than
adequate protection to even the smallest signal likely to be carried on such
a wire (usually a twisted, shielded pair) if the function of that signal is
flight critical.

--
>From: andrew.p.pr...@baesystems.com
>To: emc-p...@majordomo.ieee.org
>Subject: Re: New EU regulations - civil aviation
>Date: Tue, Sep 17, 2002, 1:56 AM
>

By unscreened I mean the cables have no overall screen as used by military
cableforms.

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RE: thermocouple welder

[Roman, Dan]

Brian,

I use a "Hot Spot" welder from DCC Corp.  Works quite well and even comes
with green tinted safety glasses (as suggested by an earlier poster).  Here
is a link to a description of it, I think they give company contact info as
well:

http://www.thomasregister.com/olc/dcc/hot2.htm

Dan

-Original Message-
From: Brian McAuliffe [mailto:i...@mcac.ie]
Sent: Tuesday, September 17, 2002 11:14 AM
To: Emc-Pstc Post
Subject: thermocouple welder



any recommendations for a fine-wire thermocouple tip welder ?

Brian


Brian McAuliffe

MCA Compliance Solutions Ltd
Unit 2 Lissane Business Park|Clarecastle|Co.Clare|Ireland

w: www.mcac.ie
e: i...@mcac.ie
t: +353 (0)65 6823452
m: +353 (0)87 2352554

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Re: CE Marking for Passive speakers

[SOUNDSURFR]

John,

You wrote, with regard to passive speakers and headphones:

The absence of active components is irrelevant. The EMC and Low Voltage
Directives apply. 


How is it that the Directives apply to products that do not carry an 
electrical rating?

And in response to the question of getting a commission ruling on the issue, 
you wrote:

>>>It's already established. You don't need a 'golden word'.

Where exactly is it established, and by whom?

Regards,


Greg Galluccio
www.productapprovals.com


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