Re: [PSES] Spread-Spectrum Clock Question

[Bill Owsley]

Probably explains why my wifi link is slower than advertised!!!  It is the 
error correction time...



 From: Ed Price 
To: emc-p...@ieee.org 
Sent: Friday, February 10, 2012 2:29 AM
Subject: RE: [PSES] Spread-Spectrum Clock Question
 

And we’ve been arguing about it ever since.
 
The use of a QP detector and the 120 kHz defined RBW makes sense if you are 
trying to test to demonstrate minimum harm to a communications channel using AM 
modulation. Thus, if you do something to your clock that results in an 
indicated signal reduction, then this is a valid thing, because you will also 
reduce your interfering potential to that AM communication channel.
 
But what happens when you have a digital bit-stream? Your dithered clock jumps 
around, and at one point in time, sits right in the passband of that 
communication channel. So let’s say it sits there for 10 microseconds. If that 
channel is running a 100 MB data rate, then you have just turned about a 
thousand 1’s and 0’s into 1’s. Error correction and/or redundant transmission 
might keep things going, but you will definitely degrade the performance.
 
Calling a dithered clock a “spread spectrum” signal is just not right; the 
energy is not spread, it’s all there, somewhere, and then all there again, 
somewhere else.
 
 
Ed Price
El Cajon, CA
USA
 
From:Bill Owsley [mailto:wdows...@yahoo.com] 
Sent: Thursday, February 09, 2012 8:59 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spread-Spectrum Clock Question
 
yeah! what John says.
He now owns the consulting business started by Don Bush, and worked with all 
those guys long ago.|
ps. I don't recall ever meeting John.  But I did work with the guys listed on 
the patent, when Lexmark was IBM.
I recall the big surprise for me with this SSCG was we (Boca) thought that the 
FCC would never agree to this kind of "cheating" on emissions and when the FCC 
came out with their ruling that it was okay, we were all in disbelief!!!
 



From:John Barnes 
To: neve...@comcast.net; EMC-PSTC@LISTSERV.IEEE.ORG 
Sent: Thursday, February 9, 2012 10:07 PM
Subject: Re: Spread-Spectrum Clock Question

Neven,
I've worked with the EMC Engineers at Lexmark who invented the
spread-spectrum clock generator (SSCG), since before they started its
development.  I used SSCG in a number of products that I designed at
Lexmark.  Below is my understanding of how SSCG works, based on numerous
discussions with the *real* experts.

Consider an ordinary clock generator, that creates a continuous 
near-trapezoidal waveform switching between Alow and Ahigh volts at
frequency f1 Hertz.  Depending on the duty cycle, rise time, fall time,
shape of the rising edge, and shape of the falling edge, the frequency
spectrum of this clock will have:
*  A DC bias, A0 volts, somewhere between Alow and Ahigh volts.
*  A fundamental of A1 volts at f1 (and -f1) Hertz.
*  A second harmonic of A2 volts at f2 = 2*f1 (and -f2) Hertz.
*  A third harmonic of A3 volts at f3 = 3*f1 (and -f3) Hertz.
  ...
*  An Nth harmonic of AN volts at fN =N*f1 (and -fN) Hertz.
  ...

If we tune over frequency with a peak/quasipeak/average detector having
a bandpass filter with bandwidth BW < f1 Hertz, we will see steady
spikes at frequencies f1, f2, f3, etc. with amplitudes A1, A2, A3, etc.
volts, each having a width BW Hertz and a shape reflecting the filter's 
s21 shape factor.  (If BW > f1 Hertz, at frequency f Hertz we will see a
composite of all of the spikes between f-BW/2 and f+BW/2 Hertz,
attenuated by the filter's shape factor, which is much messier to deal
with conceptually.)  

A given detector has a finite risetime for a signal that appears within
its filter's bandwidth, and an associated falltime when *no* signal is
seen within its filter's bandwidth.  For a peak detector, this risetime
is very short, and the falltime essentially infinite.  For a quasipeak
detector, the risetime is somewhat longer, and both the risetime and the
falltime are finite, as specified by some standard-- or by the parts
chosen and how the detector is built.  The quasipeak detector imitates
the response of human ears and eyes, where a single brief stimulus
doesn't affect us much, but an on-going stimulus-- even at a much lower
level-- bugs the dickens out of us (Chinese water torture).  An average
detector has a risetime and a falltime that extend over several (many)
cycles of our clock, so it measures the average value.  

With a continuous clock at frequency f1, a peak, quasipeak, and average
detector will all measure close to:
*  A1 volts at f1 Hertz.
*  A2 volts at f2 = 2*f1 Hertz.
*  A3 volts at f3 = 3*f1 Hertz.
  ...
*  AN volts at fN =N*f1 Hertz.
  ...



Now let us vary (dither) the clock frequency between f1- and f1+ Hertz,
at some reasonably-fast rate, without changing the rising and falling
edges of the clock (i.e. spread-spectrum clock generator (SSCG)):  
*  The DC bias, A0 volts, stays about the same.
*  The fund

Re: [PSES] Spread-Spectrum Clock Question

[Ed Price]

And we've been arguing about it ever since.

 

The use of a QP detector and the 120 kHz defined RBW makes sense if you are
trying to test to demonstrate minimum harm to a communications channel using
AM modulation. Thus, if you do something to your clock that results in an
indicated signal reduction, then this is a valid thing, because you will
also reduce your interfering potential to that AM communication channel.

 

But what happens when you have a digital bit-stream? Your dithered clock
jumps around, and at one point in time, sits right in the passband of that
communication channel. So let's say it sits there for 10 microseconds. If
that channel is running a 100 MB data rate, then you have just turned about
a thousand 1's and 0's into 1's. Error correction and/or redundant
transmission might keep things going, but you will definitely degrade the
performance.

 

Calling a dithered clock a "spread spectrum" signal is just not right; the
energy is not spread, it's all there, somewhere, and then all there again,
somewhere else.

 

 

Ed Price

El Cajon, CA

USA

 

From: Bill Owsley [mailto:wdows...@yahoo.com] 
Sent: Thursday, February 09, 2012 8:59 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Spread-Spectrum Clock Question

 

yeah! what John says.

He now owns the consulting business started by Don Bush, and worked with all
those guys long ago.|

ps. I don't recall ever meeting John.  But I did work with the guys listed
on the patent, when Lexmark was IBM.

I recall the big surprise for me with this SSCG was we (Boca) thought that
the FCC would never agree to this kind of "cheating" on emissions and when
the FCC came out with their ruling that it was okay, we were all in
disbelief!!!

 

  _  

From: John Barnes 
To: neve...@comcast.net; EMC-PSTC@LISTSERV.IEEE.ORG 
Sent: Thursday, February 9, 2012 10:07 PM
Subject: Re: Spread-Spectrum Clock Question


Neven,
I've worked with the EMC Engineers at Lexmark who invented the
spread-spectrum clock generator (SSCG), since before they started its
development.  I used SSCG in a number of products that I designed at
Lexmark.  Below is my understanding of how SSCG works, based on numerous
discussions with the *real* experts.

Consider an ordinary clock generator, that creates a continuous 
near-trapezoidal waveform switching between Alow and Ahigh volts at
frequency f1 Hertz.  Depending on the duty cycle, rise time, fall time,
shape of the rising edge, and shape of the falling edge, the frequency
spectrum of this clock will have:
*  A DC bias, A0 volts, somewhere between Alow and Ahigh volts.
*  A fundamental of A1 volts at f1 (and -f1) Hertz.
*  A second harmonic of A2 volts at f2 = 2*f1 (and -f2) Hertz.
*  A third harmonic of A3 volts at f3 = 3*f1 (and -f3) Hertz.
  ...
*  An Nth harmonic of AN volts at fN =N*f1 (and -fN) Hertz.
  ...

If we tune over frequency with a peak/quasipeak/average detector having
a bandpass filter with bandwidth BW < f1 Hertz, we will see steady
spikes at frequencies f1, f2, f3, etc. with amplitudes A1, A2, A3, etc.
volts, each having a width BW Hertz and a shape reflecting the filter's 
s21 shape factor.  (If BW > f1 Hertz, at frequency f Hertz we will see a
composite of all of the spikes between f-BW/2 and f+BW/2 Hertz,
attenuated by the filter's shape factor, which is much messier to deal
with conceptually.)  

A given detector has a finite risetime for a signal that appears within
its filter's bandwidth, and an associated falltime when *no* signal is
seen within its filter's bandwidth.  For a peak detector, this risetime
is very short, and the falltime essentially infinite.  For a quasipeak
detector, the risetime is somewhat longer, and both the risetime and the
falltime are finite, as specified by some standard-- or by the parts
chosen and how the detector is built.  The quasipeak detector imitates
the response of human ears and eyes, where a single brief stimulus
doesn't affect us much, but an on-going stimulus-- even at a much lower
level-- bugs the dickens out of us (Chinese water torture).  An average
detector has a risetime and a falltime that extend over several (many)
cycles of our clock, so it measures the average value.  

With a continuous clock at frequency f1, a peak, quasipeak, and average
detector will all measure close to:
*  A1 volts at f1 Hertz.
*  A2 volts at f2 = 2*f1 Hertz.
*  A3 volts at f3 = 3*f1 Hertz.
  ...
*  AN volts at fN =N*f1 Hertz.
  ...



Now let us vary (dither) the clock frequency between f1- and f1+ Hertz,
at some reasonably-fast rate, without changing the rising and falling
edges of the clock (i.e. spread-spectrum clock generator (SSCG)):  
*  The DC bias, A0 volts, stays about the same.
*  The fundamental is still about A1 volts, but it varies between 
  f1- and f1+ Hertz.
*  The second harmonic is still about A2 volts, but it varies between
  f2- = 2*f1- and f2+ = 2*f1+ Hertz.
*  The third harmonic is still about A3 volts, but it varies bwteen
  f3- = 3*f1- and f3+ = 3*f1+ Hert

Re: [PSES] Spread-Spectrum Clock Question

[Bill Owsley]

The common spreading freq at the time meant that the interference passed thru 
the sensitive band at a frequency higher than our human visual and auditory 
perceptions, (It could be detected by comparing side by side, two systems, one 
with and one without) but for those of us that opinionated that is was " 
cheating", we worked to find the beat frequencies and showed that.  Our 
position did not prevail, nor did our purist view of thou shalt not interfere, 
QP or peak!  Besides, it was new, and since our frequency identification for 
further QP measurements involved peak measurements, this gave us more/freq's 
info to examine.   Those of us on the design side; some counted on the SSCG, 
and others of us ensured our designs did not need SSCG.
We no longer have analog TV in the US where we could place "hum" bars, but if 
some of this is in the FM band, and computers used work are 
frequencies comparable to the FM band, it could make a station sound rather 
weak due to the interference.  But only us technical guys would recognize it!  
And one reason why the SSCG modulation was 50 kHz in general; that beating with 
the highest audio frequency, was still 25 kHz.
Only young girls could hear it and not many of them!  



 From: Ken Javor 
To: "EMC-PSTC@LISTSERV.IEEE.ORG"  
Sent: Friday, February 10, 2012 12:16 AM
Subject: Re: Spread-Spectrum Clock Question
 

Re: Spread-Spectrum Clock Question 
Why is a spread-spectrum clock cheating?

If the measurement BW is an accurate portrayal of the victims protected by the 
levied requirement, and if the QP detector is an accurate assessment of the 
nuisance value of the interfering signal modulation, then why is spreading the 
spectrum over a range of frequencies cheating, when only one victim frequency 
can be received by a given listener, and the interference to that one channel 
has been reduced to the level required by the limit?

Now if the victim receiver has a wide enough BW so that the dithered clock 
harmonics are all in band tot he victim receiver, that could be a problem. That 
occurs with broadcast television reception, with a 4 MHz BW in the old analog 
days, and even wider now. Haven’t experienced it myself, but have heard that a 
dithered clock harmonic can actually cause more of a nuisance to television 
reception than if the clock was a fixed frequency.  But that is a special case.

What is the reason for the “cheating” verdict?
  
Ken Javor
Phone: (256) 650-5261



From: Bill Owsley 
Reply-To: Bill Owsley 
Date: Thu, 9 Feb 2012 20:59:01 -0800 (PST)
To: "jrbar...@iglou.com" , "neve...@comcast.net" 
, "EMC-PSTC@LISTSERV.IEEE.ORG" 
Subject: Re: Spread-Spectrum Clock Question

yeah! what John says.
He now owns the consulting business started by Don Bush, and worked with all 
those guys long ago.|
ps. I don't recall ever meeting John.  But I did work with the guys listed on 
the patent, when Lexmark was IBM.
I recall the big surprise for me with this SSCG was we (Boca) thought that the 
FCC would never agree to this kind of "cheating" on emissions and when the FCC 
came out with their ruling that it was okay, we were all in disbelief!!!

  
 
 
 

  From: John Barnes 
 To: neve...@comcast.net; EMC-PSTC@LISTSERV.IEEE.ORG 
 Sent: Thursday, February 9, 2012 10:07 PM
 Subject: Re: Spread-Spectrum Clock Question
 
 
Neven,
I've worked with the EMC Engineers at Lexmark who invented the
spread-spectrum clock generator (SSCG), since before they started its
development.  I used SSCG in a number of products that I designed at
Lexmark.  Below is my understanding of how SSCG works, based on numerous
discussions with the *real* experts.

Consider an ordinary clock generator, that creates a continuous 
near-trapezoidal waveform switching between Alow and Ahigh volts at
frequency f1 Hertz.  Depending on the duty cycle, rise time, fall time,
shape of the rising edge, and shape of the falling edge, the frequency
spectrum of this clock will have:
*  A DC bias, A0 volts, somewhere between Alow and Ahigh volts.
*  A fundamental of A1 volts at f1 (and -f1) Hertz.
*  A second harmonic of A2 volts at f2 = 2*f1 (and -f2) Hertz.
*  A third harmonic of A3 volts at f3 = 3*f1 (and -f3) Hertz.
   ...
*  An Nth harmonic of AN volts at fN =N*f1 (and -fN) Hertz.
   ...

If we tune over frequency with a peak/quasipeak/average detector having
a bandpass filter with bandwidth BW < f1 Hertz, we will see steady
spikes at frequencies f1, f2, f3, etc. with amplitudes A1, A2, A3, etc.
volts, each having a width BW Hertz and a shape reflecting the filter's 
s21 shape factor.  (If BW > f1 Hertz, at frequency f Hertz we will see a
composite of all of the spikes between f-BW/2 and f+BW/2 Hertz,
attenuated by the filter's shape factor, which is much messier to deal
with conceptually.)  

A given detector has a finite risetime for a signal that appears within
its filter's bandwidth, and an associated falltim

Re: [PSES] Spread-Spectrum Clock Question

[Ken Javor]

Why is a spread-spectrum clock cheating?

If the measurement BW is an accurate portrayal of the victims protected by
the levied requirement, and if the QP detector is an accurate assessment of
the nuisance value of the interfering signal modulation, then why is
spreading the spectrum over a range of frequencies cheating, when only one
victim frequency can be received by a given listener, and the interference
to that one channel has been reduced to the level required by the limit?

Now if the victim receiver has a wide enough BW so that the dithered clock
harmonics are all in band tot he victim receiver, that could be a problem.
That occurs with broadcast television reception, with a 4 MHz BW in the old
analog days, and even wider now. Haven¹t experienced it myself, but have
heard that a dithered clock harmonic can actually cause more of a nuisance
to television reception than if the clock was a fixed frequency.  But that
is a special case.

What is the reason for the ³cheating² verdict?
  
Ken Javor
Phone: (256) 650-5261



From: Bill Owsley 
Reply-To: Bill Owsley 
Date: Thu, 9 Feb 2012 20:59:01 -0800 (PST)
To: "jrbar...@iglou.com" , "neve...@comcast.net"
, "EMC-PSTC@LISTSERV.IEEE.ORG"

Subject: Re: Spread-Spectrum Clock Question

yeah! what John says.
He now owns the consulting business started by Don Bush, and worked with all
those guys long ago.|
ps. I don't recall ever meeting John.  But I did work with the guys listed
on the patent, when Lexmark was IBM.
I recall the big surprise for me with this SSCG was we (Boca) thought that
the FCC would never agree to this kind of "cheating" on emissions and when
the FCC came out with their ruling that it was okay, we were all in
disbelief!!!

  
 
 
  

  From: John Barnes 
 To: neve...@comcast.net; EMC-PSTC@LISTSERV.IEEE.ORG
 Sent: Thursday, February 9, 2012 10:07 PM
 Subject: Re: Spread-Spectrum Clock Question
  
 
Neven,
I've worked with the EMC Engineers at Lexmark who invented the
spread-spectrum clock generator (SSCG), since before they started its
development.  I used SSCG in a number of products that I designed at
Lexmark.  Below is my understanding of how SSCG works, based on numerous
discussions with the *real* experts.

Consider an ordinary clock generator, that creates a continuous
near-trapezoidal waveform switching between Alow and Ahigh volts at
frequency f1 Hertz.  Depending on the duty cycle, rise time, fall time,
shape of the rising edge, and shape of the falling edge, the frequency
spectrum of this clock will have:
*  A DC bias, A0 volts, somewhere between Alow and Ahigh volts.
*  A fundamental of A1 volts at f1 (and -f1) Hertz.
*  A second harmonic of A2 volts at f2 = 2*f1 (and -f2) Hertz.
*  A third harmonic of A3 volts at f3 = 3*f1 (and -f3) Hertz.
   ...
*  An Nth harmonic of AN volts at fN =N*f1 (and -fN) Hertz.
   ...

If we tune over frequency with a peak/quasipeak/average detector having
a bandpass filter with bandwidth BW < f1 Hertz, we will see steady
spikes at frequencies f1, f2, f3, etc. with amplitudes A1, A2, A3, etc.
volts, each having a width BW Hertz and a shape reflecting the filter's
s21 shape factor.  (If BW > f1 Hertz, at frequency f Hertz we will see a
composite of all of the spikes between f-BW/2 and f+BW/2 Hertz,
attenuated by the filter's shape factor, which is much messier to deal
with conceptually.)

A given detector has a finite risetime for a signal that appears within
its filter's bandwidth, and an associated falltime when *no* signal is
seen within its filter's bandwidth.  For a peak detector, this risetime
is very short, and the falltime essentially infinite.  For a quasipeak
detector, the risetime is somewhat longer, and both the risetime and the
falltime are finite, as specified by some standard-- or by the parts
chosen and how the detector is built.  The quasipeak detector imitates
the response of human ears and eyes, where a single brief stimulus
doesn't affect us much, but an on-going stimulus-- even at a much lower
level-- bugs the dickens out of us (Chinese water torture).  An average
detector has a risetime and a falltime that extend over several (many)
cycles of our clock, so it measures the average value.

With a continuous clock at frequency f1, a peak, quasipeak, and average
detector will all measure close to:
*  A1 volts at f1 Hertz.
*  A2 volts at f2 = 2*f1 Hertz.
*  A3 volts at f3 = 3*f1 Hertz.
   ...
*  AN volts at fN =N*f1 Hertz.
   ...



Now let us vary (dither) the clock frequency between f1- and f1+ Hertz,
at some reasonably-fast rate, without changing the rising and falling
edges of the clock (i.e. spread-spectrum clock generator (SSCG)):
*  The DC bias, A0 volts, stays about the same.
*  The fundamental is still about A1 volts, but it varies between
   f1- and f1+ Hertz.
*  The second harmonic is still about A2 volts, but it varies between
   f2- = 2*f1- and f2+ = 2*f1+ Hertz.
*  The third harmonic is still about A3 volts, but it varies bwteen
   f3- = 3*f1- and f3+ = 3*f1+ Hertz.
   ...
*

Re: [PSES] Spread-Spectrum Clock Question

[Bill Owsley]

yeah! what John says.
He now owns the consulting business started by Don Bush, and worked with all 
those guys long ago.|
ps. I don't recall ever meeting John.  But I did work with the guys listed on 
the patent, when Lexmark was IBM.
I recall the big surprise for me with this SSCG was we (Boca) thought that the 
FCC would never agree to this kind of "cheating" on emissions and when the FCC 
came out with their ruling that it was okay, we were all in disbelief!!!



 From: John Barnes 
To: neve...@comcast.net; EMC-PSTC@LISTSERV.IEEE.ORG 
Sent: Thursday, February 9, 2012 10:07 PM
Subject: Re: Spread-Spectrum Clock Question
 
Neven,
I've worked with the EMC Engineers at Lexmark who invented the
spread-spectrum clock generator (SSCG), since before they started its
development.  I used SSCG in a number of products that I designed at
Lexmark.  Below is my understanding of how SSCG works, based on numerous
discussions with the *real* experts.

Consider an ordinary clock generator, that creates a continuous 
near-trapezoidal waveform switching between Alow and Ahigh volts at
frequency f1 Hertz.  Depending on the duty cycle, rise time, fall time,
shape of the rising edge, and shape of the falling edge, the frequency
spectrum of this clock will have:
*  A DC bias, A0 volts, somewhere between Alow and Ahigh volts.
*  A fundamental of A1 volts at f1 (and -f1) Hertz.
*  A second harmonic of A2 volts at f2 = 2*f1 (and -f2) Hertz.
*  A third harmonic of A3 volts at f3 = 3*f1 (and -f3) Hertz.
   ...
*  An Nth harmonic of AN volts at fN =N*f1 (and -fN) Hertz.
   ...

If we tune over frequency with a peak/quasipeak/average detector having
a bandpass filter with bandwidth BW < f1 Hertz, we will see steady
spikes at frequencies f1, f2, f3, etc. with amplitudes A1, A2, A3, etc.
volts, each having a width BW Hertz and a shape reflecting the filter's 
s21 shape factor.  (If BW > f1 Hertz, at frequency f Hertz we will see a
composite of all of the spikes between f-BW/2 and f+BW/2 Hertz,
attenuated by the filter's shape factor, which is much messier to deal
with conceptually.)  

A given detector has a finite risetime for a signal that appears within
its filter's bandwidth, and an associated falltime when *no* signal is
seen within its filter's bandwidth.  For a peak detector, this risetime
is very short, and the falltime essentially infinite.  For a quasipeak
detector, the risetime is somewhat longer, and both the risetime and the
falltime are finite, as specified by some standard-- or by the parts
chosen and how the detector is built.  The quasipeak detector imitates
the response of human ears and eyes, where a single brief stimulus
doesn't affect us much, but an on-going stimulus-- even at a much lower
level-- bugs the dickens out of us (Chinese water torture).  An average
detector has a risetime and a falltime that extend over several (many)
cycles of our clock, so it measures the average value.  

With a continuous clock at frequency f1, a peak, quasipeak, and average
detector will all measure close to:
*  A1 volts at f1 Hertz.
*  A2 volts at f2 = 2*f1 Hertz.
*  A3 volts at f3 = 3*f1 Hertz.
   ...
*  AN volts at fN =N*f1 Hertz.
   ...



Now let us vary (dither) the clock frequency between f1- and f1+ Hertz,
at some reasonably-fast rate, without changing the rising and falling
edges of the clock (i.e. spread-spectrum clock generator (SSCG)):  
*  The DC bias, A0 volts, stays about the same.
*  The fundamental is still about A1 volts, but it varies between 
   f1- and f1+ Hertz.
*  The second harmonic is still about A2 volts, but it varies between
   f2- = 2*f1- and f2+ = 2*f1+ Hertz.
*  The third harmonic is still about A3 volts, but it varies bwteen
   f3- = 3*f1- and f3+ = 3*f1+ Hertz.
   ...
*  The Nth harmonic is still about AN volts, but it varies between
   fN- = N*f1- and fN+ = N*f1+ Hertz.
   ...

Essentially, over time, the fundamental and its harmonics each occupy a
band of frequencies.  At high-enough harmonics 
        (f1+ + f1-)/2
   N >= -
         f1+ - f1-
these bands will overlap one another, but hopefully the amplitudes of
the harmonics have dropped enough that these overlaps won't cause us a
problem.  

Instantaneously, if the clock is at frequency f1x, f1- <= f1x <= f1+,
we still have spikes at f1x, 2*f1x, 3*f1x, ..., N*f1x, ...

But if we look at the SSCG clock with a detector with a bandpass filter
set at frequency f Hertz, within one of these frequency bands, either
*  The fundamental or harmonic remains within the bandwidth (BW Hertz)
   of the filter-- and we measure essentially the same amplitude as for
   a constant clock.
       OR
*  The harmonic flits in and out of the filter's bandwidth, thus we see
   only part of the signal.

If we flit through the filter's bandwidth fast enough-- and infrequently
enough-- the detector doesn't have time to respond fully, and it *looks
like* the fundamental/harmonic is much lower than it really is!

Since most of th

Re: [PSES] Spread-Spectrum Clock Question

[Bill Owsley]

Neven, 
you are right on with observations.  Except for your expectation.
SSC works only with QP measurements.  Peak does not show any reduction using 
the 'normal' measuring techniques.|
The modulating frequency I'm familiar with has been 50 kHz.|
ps.  If implemented using small steps, or something other than the Hersey kiss 
timing, you may find that the EUT now fails at two frequencies, one at each end 
of the spread!
pps.  Those "small steps" can cause all sorts of mischief with PLL's, as they 
try to correct for a step that may not be small for the control loop. More 
steps, of a smaller increment is needed, or just use a VCO that will modulate 
the frequency with the voltage and control that voltage appropriately.
The patent on this is held by Lexmark and Keith Hardin, Don Bush (RIP), etc. if 
I recall correctly.  Maybe expired by now.
Lexmark was previously one of the printer/keyboard divisions of IBM, and this 
SSC was used by them to pass EMC, well before the patent was granted.


 From: Ken Wyatt 
To: neve...@comcast.net 
Cc: EMC-PSTC@LISTSERV.IEEE.ORG 
Sent: Thursday, February 9, 2012 7:50 PM
Subject: Re: [PSES] Spread-Spectrum Clock Question
 

Neven,
Your suspicion regarding the modulating frequency is on the right track. 
Normally, the mod freq is set just above the audio range. There's something 
very wrong if the specs only allow 3 to 100 Hz. Is that a misprint perhaps?

You should be able to see the "spread" harmonics easily at 120 kHz RBW. If you 
don't see that, it's just not being modulated correctly.

If you provide the specific SSC chip used, the group could probably help you 
better.

Cheers, Ken
___
Kenneth Wyatt
Wyatt Technical Services LLC
Woodland Park, CO
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On Feb 9, 2012, at 5:32 PM, Neven Pischl wrote:

Hello,
> 
>I wonder if anyone can help with a question I have on spread spectrum clock 
>(SSC).
> 
>I am trying to validate the effectiveness of a SSC chip to reduce emission. I 
>measure with the peak detector. With the SSC enabled (up to 2.5% 
>down-spread) I expect the level measured with a spectrum analyzer to go down 
>at the fundamental and even more at the harmonics, when compared with the peak 
>levels without the SSC enabled. The problem is that I only see that the 
>frequency gets spread but the peak value stays exactly the same with and 
>without the modulation, using 100kHz or 120kHz RBW of the analyzer. This 
>happens at the fundamental as well as at the harmonics, so there is absolutely 
>no reduction in the measured peak amplitude, it just looks wider.
>  
>What is interesting is that if I reduce the RBW on the analyzer down to 
>1-3kHz, I see the expected result on the analyzer. The frequency is spread and 
>the peak level with the spread is lower when compared with the peak level 
>measured without the SSC enabled, the same difference as one can see in 
>various papers and material on SSC, and which I also measured many times in 
>the past.
> 
>However, that is not the required RBW that I must use between 30MHz and 1GHzs, 
>so we have a problem.
> 
>I believe there is something in the modulation scheme of the particular IC 
>that must be changed to make it work when measured with 120 MHz RBW but I am 
>not sure what.
> 
>Some of the modulation parameters:
>Triangular waveform, quasi-linear ramp up and linear ramp down.
>Linear is actually represented with “small” discrete steps.
>Frequency range of the modulating waveform is very low, it can be adjusted 
>roughly between 3Hz and about 100 Hz.
>T he SSC devices on the market normally use about 30-40 kHz for the modulating 
>waveform
> 
>I wonder if the modulating frequency has something to do with the observed 
>lack of amplitude reduction. The equations that describe the emi-reduction do 
>not contain the modulating frequency as a factor so it "should" not be a 
>facotr - BUT - maybe I am not taking into account the relation with the 
>measurement settings and non-ideal world.
>  
>Any sugetions or comments, links to reference article, App Notes, etc??
> 
>Regards, Neven-
>
>
>This message is from the IEEE Product Safety Engineering Society emc-pstc 
>discussion list. To post a message to the list, send your e-mail to 
>
>All emc-pstc postings are archived and searchable on the web 
>at: http://www.ieee-pses.org/emc-pstc.html
>Attachments are not permitted but the IEEE PSES Online Communities site 
>at http://product-compliance.oc.ieee.org/ can be used for graphics (in 
>well-used formats), large files, etc.
>Website: http://www.ieee-pses.org/
>Instructions: http://listserv.ieee.org/request/user-guide.html
>List rules: http://www.ieee-pses.org/listrules.html
>For help, send mail to the list administrators:
>Scott Douglas 
>Mike Cantwell 
>For policy questions, send mail to:
>Jim Bacher 
>David Heald 
-

Re: [PSES] Melting BNC connectors

[Doug Smith]

Hi John and the group,

There were no markings of any kind on the devices. I bought several from 
a surplus house here in Silicon Valley so the source is unknown. Easy 
problem to test for though, buy one first, heat it up, results obvious.


Doug

On 2/9/12 5:52 AM, John Woodgate wrote:
In message 
, 
dated Thu, 9 Feb 2012, N.Shani  writes:


Doug, you could do all of us a great service if you mentioned what & 
how the connector was marked, or where it was sourced.
We all take short cuts every so often, so a Buyer Beware with a bit 
more details will be appreciated.


I don't see any great problem in the use of pewter or similar as the 
body of a connector for indoor use. Pewter just goes dull on exposure 
to the air; it does not normally corrode, although alkalis should be 
avoided. In any case, I expect the connector would be nickel-plated.


I didn't find any resistivity data, but tin is about 7 times the 
resistance of copper. However, the current density in connector bodies 
is usually very low.


--
---
___  _   Doug Smith
 \  / )  P.O. Box 1457
  =  Los Gatos, CA 95031-1457
   _ / \ / \ _   TEL/FAX: 408-356-4186/358-3799
 /  /\  \ ] /  /\  \ Mobile:  408-858-4528
|  q-( )  |  o  |Email:   d...@dsmith.org
 \ _ /]\ _ / Website: http://www.dsmith.org
---

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Re: [PSES] Spread-Spectrum Clock Question

[John Barnes]

Neven,
I've worked with the EMC Engineers at Lexmark who invented the
spread-spectrum clock generator (SSCG), since before they started its
development.  I used SSCG in a number of products that I designed at
Lexmark.  Below is my understanding of how SSCG works, based on numerous
discussions with the *real* experts.

Consider an ordinary clock generator, that creates a continuous 
near-trapezoidal waveform switching between Alow and Ahigh volts at
frequency f1 Hertz.  Depending on the duty cycle, rise time, fall time,
shape of the rising edge, and shape of the falling edge, the frequency
spectrum of this clock will have:
*  A DC bias, A0 volts, somewhere between Alow and Ahigh volts.
*  A fundamental of A1 volts at f1 (and -f1) Hertz.
*  A second harmonic of A2 volts at f2 = 2*f1 (and -f2) Hertz.
*  A third harmonic of A3 volts at f3 = 3*f1 (and -f3) Hertz.
   ...
*  An Nth harmonic of AN volts at fN =N*f1 (and -fN) Hertz.
   ...

If we tune over frequency with a peak/quasipeak/average detector having
a bandpass filter with bandwidth BW < f1 Hertz, we will see steady
spikes at frequencies f1, f2, f3, etc. with amplitudes A1, A2, A3, etc.
volts, each having a width BW Hertz and a shape reflecting the filter's 
s21 shape factor.  (If BW > f1 Hertz, at frequency f Hertz we will see a
composite of all of the spikes between f-BW/2 and f+BW/2 Hertz,
attenuated by the filter's shape factor, which is much messier to deal
with conceptually.)  

A given detector has a finite risetime for a signal that appears within
its filter's bandwidth, and an associated falltime when *no* signal is
seen within its filter's bandwidth.  For a peak detector, this risetime
is very short, and the falltime essentially infinite.  For a quasipeak
detector, the risetime is somewhat longer, and both the risetime and the
falltime are finite, as specified by some standard-- or by the parts
chosen and how the detector is built.  The quasipeak detector imitates
the response of human ears and eyes, where a single brief stimulus
doesn't affect us much, but an on-going stimulus-- even at a much lower
level-- bugs the dickens out of us (Chinese water torture).  An average
detector has a risetime and a falltime that extend over several (many)
cycles of our clock, so it measures the average value.  

With a continuous clock at frequency f1, a peak, quasipeak, and average
detector will all measure close to:
*  A1 volts at f1 Hertz.
*  A2 volts at f2 = 2*f1 Hertz.
*  A3 volts at f3 = 3*f1 Hertz.
   ...
*  AN volts at fN =N*f1 Hertz.
   ...



Now let us vary (dither) the clock frequency between f1- and f1+ Hertz,
at some reasonably-fast rate, without changing the rising and falling
edges of the clock (i.e. spread-spectrum clock generator (SSCG)):  
*  The DC bias, A0 volts, stays about the same.
*  The fundamental is still about A1 volts, but it varies between 
   f1- and f1+ Hertz.
*  The second harmonic is still about A2 volts, but it varies between
   f2- = 2*f1- and f2+ = 2*f1+ Hertz.
*  The third harmonic is still about A3 volts, but it varies bwteen
   f3- = 3*f1- and f3+ = 3*f1+ Hertz.
   ...
*  The Nth harmonic is still about AN volts, but it varies between
   fN- = N*f1- and fN+ = N*f1+ Hertz.
   ...

Essentially, over time, the fundamental and its harmonics each occupy a
band of frequencies.  At high-enough harmonics 
(f1+ + f1-)/2
   N >= -
 f1+ - f1-
these bands will overlap one another, but hopefully the amplitudes of
the harmonics have dropped enough that these overlaps won't cause us a
problem.  

Instantaneously, if the clock is at frequency f1x, f1- <= f1x <= f1+,
we still have spikes at f1x, 2*f1x, 3*f1x, ..., N*f1x, ...

But if we look at the SSCG clock with a detector with a bandpass filter
set at frequency f Hertz, within one of these frequency bands, either
*  The fundamental or harmonic remains within the bandwidth (BW Hertz)
   of the filter-- and we measure essentially the same amplitude as for
   a constant clock.
   OR
*  The harmonic flits in and out of the filter's bandwidth, thus we see
   only part of the signal.

If we flit through the filter's bandwidth fast enough-- and infrequently
enough-- the detector doesn't have time to respond fully, and it *looks
like* the fundamental/harmonic is much lower than it really is!

Since most of the Radiated and Conducted Emission standards specify
limits based on quasipeak and average detectors, the spread, modulation
frequency, and modulation waveform are all controlled to "fool" the
detector as much as possible, without affecting the functionality of the
product.

In some of the products that my department and I designed at Lexmark,
SSCG lowered our *measured* emissions by up to 15dB over ordinary clock
generators.



To see how well SSCG works on your product, you really need to test it
with an appropriate quasipeak detector.  

The frequency of your modulating waveform sounds way too slow for me. 
You want to get through the filter's bandwidth 

Re: [PSES] RoHS

[Marko Radojicic]

Gary,

I share your pain.

Another possibility is to offer to pay the company for the testing. That keeps 
the liability with them, gets you your data, and all for the price you would 
pay to do it yourself.

Good luck,
Marko



 From: "McInturff, Gary" 
To: 'Marko Radojicic' ; "'EMC-PSTC@LISTSERV.IEEE.ORG'" 
 
Sent: Thursday, February 9, 2012 10:35 AM
Subject: RE: [PSES] RoHS
 

 
Guys,
all I can tell you is that this is a very large and international company, each
of you would recognized the name if I put it up. The problem is a bit recursive
– they are aware and do RoHS on materials, but because they know the
requirements and make so many materials there system still remains flooded with
existing and new materials so they prioritize and this is low on the old list
based on world usage. Unfortunately it is the best adhesive for the surface
being bonded that we know of. We aren’t big enough to move them – and by the
way I can doubt any of us on the list can move them and I know that a few of us
are on huge multinationals.
A
bit of the problem is we have used the material freely for years because
medical equipment was exempt from RoHS until just recently (or soon).
 
They
can’t jump and we can’t jump for some months, hence the quandary. Fortunately a
list member has given me a lab that can test. Even if we have to do it for a
quarter or two and be responsible for the RoHS certification ourselves it’s
really the only choice at the moment. 
 
Gary
 
From:Marko Radojicic
[mailto:radojic...@yahoo.com] 
Sent: Thursday, February 09, 2012 8:53 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS
 
+1
 
Fully agree with Chris' statement
below and with Brian Kunde's earlier message on "spot check" only.
 
Supplier management in the RoHS
domain is difficult but getting easier as more and more vendors get the message
that it is not optional.
 
...Marko
 


 
From:"James, Chris" 
To: EMC-PSTC@LISTSERV.IEEE.ORG 
Sent: Thursday, February 9, 2012 6:40 AM
Subject: Re: [PSES] RoHS
 
If the mfr will not divulge the make up of the adhesive then
switch to one who will. Any adhesive vendor placing their product into the EU
either directly or indirectly should be cognizant with the requirements of
REACH and almost certainly RoHS.
 
Chris
 
 
 
From:Kunde,
Brian [mailto:brian_ku...@lecotc.com] 
Sent: 09 February 2012 14:36
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS
 
Even if
you tested the adhesive, since you do not have manufacturing control and the
manufacturer is unable or unwilling to declare their adhesive RoHS compliant,
you will not know if the adhesive will remain RoHS compliant. The manufacturer
could change their adhesive without your knowledge. You would have to do lot
sample testing of your production.
 
The
Other Brian
 
From:emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of McInturff, Gary
Sent: Wednesday, February 08, 2012 5:34 PM
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Subject: RoHS
 
We have an adhesive with no RoHS certs, Are there RoHS capable
test labs in the US. I would presume there is some % of total content that is
allowed if one only knew what materials are in the adhesive. Not my area just
asking for a panicked compatriot. He’s looking for any means at the moment to
clear this gap.
Gary McInturff
Reliability/Compliance Engineer     
 
  
Esterline Interface Technologies Featuring
ADVANCED INPUT, MEMTRON, and LRE MEDICAL products   
600 W. Wilbur Avenue
Coeur d’Alene, ID  83815-9496
Office:208-635-8306
Cell:  509 868 2279
Toll Free: 800-444-5923 X 1238
gary.mcintu...@esterline.com
 
 
www.esterline.com/interfacetechnologies
 
Technology, Innovation, Performance... 
 
 
-

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Notice: This communication may contain confidential information intended for
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emc-pstc postings are arch

Re: [PSES] Spread-Spectrum Clock Question

[Ken Javor]

There likely isn¹t much change with a peak detector, unless the frequency
changes rapidly enough that it is in the pass-band of the receiver for less
than 10 us (100 kHz RBW).  If you use a QP detector, you will see a big
difference.
  
Ken Javor
Phone: (256) 650-5261



From: Ken Wyatt 
Date: Thu, 9 Feb 2012 17:50:40 -0700
To: 
Cc: 
Subject: Re: [PSES] Spread-Spectrum Clock Question

Neven,

Your suspicion regarding the modulating frequency is on the right track.
Normally, the mod freq is set just above the audio range. There's something
very wrong if the specs only allow 3 to 100 Hz. Is that a misprint perhaps?

You should be able to see the "spread" harmonics easily at 120 kHz RBW. If
you don't see that, it's just not being modulated correctly.

If you provide the specific SSC chip used, the group could probably help you
better.

Cheers, Ken
___
Kenneth Wyatt
Wyatt Technical Services LLC
Woodland Park, CO
Email Me!   | Web Site
  | Blog

Subscribe to Newsletter

Connect with me on LinkedIn 

On Feb 9, 2012, at 5:32 PM, Neven Pischl wrote:

> Hello,
>  
> 
> I wonder if anyone can help with a question I have on spread spectrum clock
> (SSC).
>  
> 
> I am trying to validate the effectiveness of a SSC chip to reduce emission. I
> measure with the peak detector. With the SSC enabled (up to 2.5% down-spread)
> I expect the level measured with a spectrum analyzer to go down at the
> fundamental and even more at the harmonics, when compared with the peak levels
> without the SSC enabled. The problem is that I only see that the frequency
> gets spread but the peak value stays exactly the same with and without the
> modulation, using 100kHz or 120kHz RBW of the analyzer. This happens at the
> fundamental as well as at the harmonics, so there is absolutely no reduction
> in the measured peak amplitude, it just looks wider.
>  
> What is interesting is that if I reduce the RBW on the analyzer down to
> 1-3kHz, I see the expected result on the analyzer. The frequency is spread and
> the peak level with the spread is lower when compared with the peak level
> measured without the SSC enabled, the same difference as one can see in
> various papers and material on SSC, and which I also measured many times in
> the past.
>  
> However, that is not the required RBW that I must use between 30MHz and 1GHzs,
> so we have a problem.
>  
> I believe there is something in the modulation scheme of the particular IC
> that must be changed to make it work when measured with 120 MHz RBW but I am
> not sure what.
>  
> Some of the modulation parameters:
> Triangular waveform, quasi-linear ramp up and linear ramp down.
> Linear is actually represented with ³small² discrete steps.
> Frequency range of the modulating waveform is very low, it can be adjusted
> roughly between 3Hz and about 100 Hz.
> The SSC devices on the market normally use about 30-40 kHz for the modulating
> waveform
>  
> I wonder if the modulating frequency has something to do with the observed
> lack of amplitude reduction. The equations that describe the emi-reduction do
> not contain the modulating frequency as a factor so it "should" not be a
> facotr - BUT - maybe I am not taking into account the relation with the
> measurement settings and non-ideal world.
>  
> Any sugetions or comments, links to reference article, App Notes, etc??
>  
> Regards, Neven
> -
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> 
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
> formats), large files, etc.
> Website: http://www.ieee-pses.org/
> Instructions: http://listserv.ieee.org/request/user-guide.html
> List rules: http://www.ieee-pses.org/listrules.html
> For help, send mail to the list administrators:
> Scott Douglas 
> Mike Cantwell 
> For policy questions, send mail to:
> Jim Bacher 
> David Heald 

-


This message is from the IEEE Product Safety Engineering Society emc-pstc
discussion list. To post a message to the list, send your e-mail to


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

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

Website:  http://www.ieee-pses.org/
Instructions:  http://listserv.ieee.org/request/user-g

Re: [PSES] Spread-Spectrum Clock Question

[Ken Wyatt]

Neven,

Your suspicion regarding the modulating frequency is on the right track. 
Normally, the mod freq is set just above the audio range. There's something 
very wrong if the specs only allow 3 to 100 Hz. Is that a misprint perhaps?

You should be able to see the "spread" harmonics easily at 120 kHz RBW. If you 
don't see that, it's just not being modulated correctly.

If you provide the specific SSC chip used, the group could probably help you 
better.

Cheers, Ken
___
Kenneth Wyatt
Wyatt Technical Services LLC
Woodland Park, CO
Email Me! | Web Site | Blog
Subscribe to Newsletter
Connect with me on LinkedIn

On Feb 9, 2012, at 5:32 PM, Neven Pischl wrote:

> Hello,
>  
> I wonder if anyone can help with a question I have on spread spectrum clock 
> (SSC).
>  
> I am trying to validate the effectiveness of a SSC chip to reduce emission. I 
> measure with the peak detector. With the SSC enabled (up to 2.5% down-spread) 
> I expect the level measured with a spectrum analyzer to go down at the 
> fundamental and even more at the harmonics, when compared with the peak 
> levels without the SSC enabled. The problem is that I only see that the 
> frequency gets spread but the peak value stays exactly the same with and 
> without the modulation, using 100kHz or 120kHz RBW of the analyzer. This 
> happens at the fundamental as well as at the harmonics, so there is 
> absolutely no reduction in the measured peak amplitude, it just looks wider.
>  
> What is interesting is that if I reduce the RBW on the analyzer down to 
> 1-3kHz, I see the expected result on the analyzer. The frequency is spread 
> and the peak level with the spread is lower when compared with the peak level 
> measured without the SSC enabled, the same difference as one can see in 
> various papers and material on SSC, and which I also measured many times in 
> the past.
>  
> However, that is not the required RBW that I must use between 30MHz and 
> 1GHzs, so we have a problem.
>  
> I believe there is something in the modulation scheme of the particular IC 
> that must be changed to make it work when measured with 120 MHz RBW but I am 
> not sure what.
>  
> Some of the modulation parameters:
> Triangular waveform, quasi-linear ramp up and linear ramp down.
> Linear is actually represented with “small” discrete steps.
> Frequency range of the modulating waveform is very low, it can be adjusted 
> roughly between 3Hz and about 100 Hz.
> The SSC devices on the market normally use about 30-40 kHz for the modulating 
> waveform
>  
> I wonder if the modulating frequency has something to do with the observed 
> lack of amplitude reduction. The equations that describe the emi-reduction do 
> not contain the modulating frequency as a factor so it "should" not be a 
> facotr - BUT - maybe I am not taking into account the relation with the 
> measurement settings and non-ideal world.
>  
> Any sugetions or comments, links to reference article, App Notes, etc??
>  
> Regards, Neven
> -
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc 
> discussion list. To post a message to the list, send your e-mail to 
> 
> All emc-pstc postings are archived and searchable on the web at: 
> http://www.ieee-pses.org/emc-pstc.html
> Attachments are not permitted but the IEEE PSES Online Communities site at 
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
> formats), large files, etc.
> Website: http://www.ieee-pses.org/
> Instructions: http://listserv.ieee.org/request/user-guide.html
> List rules: http://www.ieee-pses.org/listrules.html
> For help, send mail to the list administrators:
> Scott Douglas 
> Mike Cantwell 
> For policy questions, send mail to:
> Jim Bacher 
> David Heald 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


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

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

Website:  http://www.ieee-pses.org/
Instructions:  http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html

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

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

[PSES] Spread-Spectrum Clock Question

[Neven Pischl]

Hello, 



I wonder if anyone can help with a question I have on spread spectrum clock 
(SSC). 



I am trying to validate the effectiveness of a SSC chip to reduce emission. I 
measure with the peak detector. With the SSC enabled (up to 2.5% down-spread) I 
expect the level measured with a spectrum analyzer to go down at the 
fundamental and even more at the harmonics, when compared with the peak levels 
without the SSC enabled. The problem is that I only see that the frequency gets 
spread but the peak value stays exactly the same with and without the 
modulation, using 100kHz or 120kHz RBW of the analyzer. This happens at the 
fundamental as well as at the harmonics, so there is absolutely no reduction in 
the measured peak amplitude, it just looks wider. 





What is interesting is that if I reduce the RBW on the analyzer down to 1-3kHz, 
I see the expected result on the analyzer. The frequency is spread and the peak 
level with the spread is lower when compared with the peak level measured 
without the SSC enabled, the same difference as one can see in various papers 
and material on SSC, and which I also measured many times in the past. 



However, that is not the required RBW that I must use between 30MHz and 1GHzs, 
so we have a problem. 



  

I believe there is something in the modulation scheme of the particular IC that 
must be changed to make it work when measured with 120 MHz RBW but I am not 
sure what. 



  

Some of the modulation parameters: 

Triangular waveform, quasi-linear ramp up and linear ramp down. 

Linear is actually represented with “small” discrete steps. 

Frequency range of the modulating waveform is very low, it can be adjusted 
roughly between 3Hz and about 100 Hz. 



T he SSC devices on the market normally use about 30-40 kHz for the modulating 
waveform 



I wonder if the modulating frequency has something to do with the observed lack 
of amplitude reduction. The equations that describe the emi-reduction do not 
contain the modulating frequency as a factor so it "should" not be a facotr - 
BUT - maybe I am not taking into account the relation with the measurement 
settings and non-ideal world. 







Any sugetions or comments, links to reference article, App Notes, etc?? 



  

Regards, Neven

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


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

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

Website:  http://www.ieee-pses.org/
Instructions:  http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html

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

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] RoHS - an EU view

[Kunde, Brian]

Ron,

I'm referring to industrial monitoring and control instruments mentioned in 
Article 4 paragraph 3 where it would seem doesn't have to comply until 2017. 
This category is covered by the directive but seems to have a delayed start 
date.

The Other Brian

From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ron Pickard
Sent: Thursday, February 09, 2012 12:24 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] RoHS - an EU view

Hi Brian,
With the new RoHS directive's Annex I, I would find it difficult to ascertain 
any equipment (EEE) getting an exemption (please note item #11):



ANNEX I

Categories of EEE covered by this Directive

1. Large household appliances.

2. Small household appliances.

3. IT and telecommunications equipment.

4. Consumer equipment.

5. Lighting equipment.

6. Electrical and electronic tools.

7. Toys, leisure and sports equipment.

8. Medical devices.

9. Monitoring and control instruments including industrial monitoring and 
control instruments.

10. Automatic dispensers.
11. Other EEE not covered by any of the categories above.

However, Article 2 (Scope) pertains to EEE where exemptions will exist (some 
temporary).

Disclaimer: The statements below are my opinions only.
As far as your question about whether or not, I would suggest you obtain the 
advice of your legal counsel for obvious reasons. I can only suggest that you 
research this new directive and determine its particular requirements for the 
product/category to which you refer and then apply them. And if any of the 
exemptions from Annexes III and IV were to apply to components integral to your 
product, the balance of your product would likely still need to comply.

IHTH.

Best regards,
Ron

From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: Thursday, February 09, 2012 9:38 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS - an EU view

If you have a product who's category falls into an exemption for a few years 
after the 2013 date, do you still have to show the RoHS directive on your DOC 
starting 2013, but somehow state it is compliant via an exemption, or just 
don't mention it until it is required? What is the proper procedure in this 
case?

Thanks,
The Other Brian

From: emc-p...@ieee.org 
[mailto:emc-p...@ieee.org] On Behalf Of Ron 
Pickard
Sent: Thursday, February 09, 2012 11:18 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] RoHS - an EU view

To all,
In addition and especially to those that are not yet aware, please note that 
the current RoHS Directive (2002/95/EC) is now in a state of transition to the 
recast RoHS Directive 
(2011/65/EU),
 which will become mandatory on 3-Jan-2013. In a nutshell, the main points of 
this revised directive includes new applied product categories, responsibility 
party definitions/obligations and that the CE marking will then apply, which 
means that by then all declarations of conformity will most likely need to be 
updated to include this directive along with a due diligent establishment of 
conformity.

IHTH.

Best regards,
Ron

From: iun...@servomex.com 
[mailto:iun...@servomex.com]
Sent: Thursday, February 09, 2012 8:39 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS - an EU view

Group,
Given that the adhesive is unlikely to contain lead, mercury, cadmium, 
hexavalent chromium, the question is: Does it contain either Polybrominated 
biphenyls (PBB), or Polybrominated diphenyl ethers (PBDE) at concentrations 
greater than 0.1% by weight of the homogeneous material? I understand that both 
are flame retardants and used in plastics. Further the need for mandatory EU 
RoHS (2002/95/EC) compliance only kicks in when the adhesive is used in certain 
types of electrical or electronic equipment.

Another issue to be considered as far as the EU and adhesives is associated 
with the impact of the REACH Regulations (1907/2006 (as amended)). Amongst 
other things, these regulations include lists of substances whose use in 
products and their manufacture is either restricted, or requires relevant 
information to be supplied to end users. REACH includes many more substances 
than the six in RoHS, and the restrictions/requirements are not limited to 
electrical and electronic equipment.

Regards

Ian Unwin

From:"Kunde, Brian" 
mailto:brian_ku...@lecotc.com>>
To:EMC-PSTC@LISTSERV.IEEE.ORG
Date:09/02/2012 14:33
Subject:Re: [PSES] RoHS




Even if you tested the adhesive, since you do not have manufacturing control 
and the manufacturer is unable or unwilling to declare their adhesive RoHS 
compliant, you will not know if the adhesive will remain RoHS com

Re: [PSES] RoHS - an EU view

[Ron Pickard]

Hi Brian,
With the new RoHS directive's Annex I, I would find it difficult to ascertain 
any equipment (EEE) getting an exemption (please note item #11):



ANNEX I

Categories of EEE covered by this Directive

1. Large household appliances.

2. Small household appliances.

3. IT and telecommunications equipment.

4. Consumer equipment.

5. Lighting equipment.

6. Electrical and electronic tools.

7. Toys, leisure and sports equipment.

8. Medical devices.

9. Monitoring and control instruments including industrial monitoring and 
control instruments.

10. Automatic dispensers.
11. Other EEE not covered by any of the categories above.

However, Article 2 (Scope) pertains to EEE where exemptions will exist (some 
temporary).

Disclaimer: The statements below are my opinions only.
As far as your question about whether or not, I would suggest you obtain the 
advice of your legal counsel for obvious reasons. I can only suggest that you 
research this new directive and determine its particular requirements for the 
product/category to which you refer and then apply them. And if any of the 
exemptions from Annexes III and IV were to apply to components integral to your 
product, the balance of your product would likely still need to comply.

IHTH.

Best regards,
Ron

From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: Thursday, February 09, 2012 9:38 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS - an EU view

If you have a product who's category falls into an exemption for a few years 
after the 2013 date, do you still have to show the RoHS directive on your DOC 
starting 2013, but somehow state it is compliant via an exemption, or just 
don't mention it until it is required? What is the proper procedure in this 
case?

Thanks,
The Other Brian

From: emc-p...@ieee.org 
[mailto:emc-p...@ieee.org] On Behalf Of Ron 
Pickard
Sent: Thursday, February 09, 2012 11:18 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] RoHS - an EU view

To all,
In addition and especially to those that are not yet aware, please note that 
the current RoHS Directive (2002/95/EC) is now in a state of transition to the 
recast RoHS Directive 
(2011/65/EU),
 which will become mandatory on 3-Jan-2013. In a nutshell, the main points of 
this revised directive includes new applied product categories, responsibility 
party definitions/obligations and that the CE marking will then apply, which 
means that by then all declarations of conformity will most likely need to be 
updated to include this directive along with a due diligent establishment of 
conformity.

IHTH.

Best regards,
Ron

From: iun...@servomex.com 
[mailto:iun...@servomex.com]
Sent: Thursday, February 09, 2012 8:39 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS - an EU view

Group,
Given that the adhesive is unlikely to contain lead, mercury, cadmium, 
hexavalent chromium, the question is: Does it contain either Polybrominated 
biphenyls (PBB), or Polybrominated diphenyl ethers (PBDE) at concentrations 
greater than 0.1% by weight of the homogeneous material? I understand that both 
are flame retardants and used in plastics. Further the need for mandatory EU 
RoHS (2002/95/EC) compliance only kicks in when the adhesive is used in certain 
types of electrical or electronic equipment.

Another issue to be considered as far as the EU and adhesives is associated 
with the impact of the REACH Regulations (1907/2006 (as amended)). Amongst 
other things, these regulations include lists of substances whose use in 
products and their manufacture is either restricted, or requires relevant 
information to be supplied to end users. REACH includes many more substances 
than the six in RoHS, and the restrictions/requirements are not limited to 
electrical and electronic equipment.

Regards

Ian Unwin

From:"Kunde, Brian" 
mailto:brian_ku...@lecotc.com>>
To:EMC-PSTC@LISTSERV.IEEE.ORG
Date:09/02/2012 14:33
Subject:Re: [PSES] RoHS




Even if you tested the adhesive, since you do not have manufacturing control 
and the manufacturer is unable or unwilling to declare their adhesive RoHS 
compliant, you will not know if the adhesive will remain RoHS compliant. The 
manufacturer could change their adhesive without your knowledge. You would have 
to do lot sample testing of your production.

The Other Brian

From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On 
Behalf Of McInturff, Gary
Sent: Wednesday, February 08, 2012 5:34 PM
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Subject: RoHS

We have an adhesive with no RoHS certs, Are there RoHS capable test labs in the 
US. I would pre

Re: [PSES] RoHS

[Marko Radojicic]

+1

Fully agree with Chris' statement below and with Brian Kunde's earlier message 
on "spot check" only.

Supplier management in the RoHS domain is difficult but getting easier as more 
and more vendors get the message that it is not optional.

...Marko



 From: "James, Chris" 
To: EMC-PSTC@LISTSERV.IEEE.ORG 
Sent: Thursday, February 9, 2012 6:40 AM
Subject: Re: [PSES] RoHS
 

If the mfr will not divulge the make up of the adhesive then switch to one who 
will. Any adhesive vendor placing their product into the EU either directly or 
indirectly should be cognizant with the requirements of REACH and almost 
certainly RoHS.
 
Chris
 
 
 
From:Kunde, Brian [mailto:brian_ku...@lecotc.com] 
Sent: 09 February 2012 14:36
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS
 
Even if you tested the adhesive, since you do not have manufacturing control 
and the manufacturer is unable or unwilling to declare their adhesive RoHS 
compliant, you will not know if the adhesive will remain RoHS compliant. The 
manufacturer could change their adhesive without your knowledge. You would have 
to do lot sample testing of your production.
 
The Other Brian
 
From:emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of McInturff, Gary
Sent: Wednesday, February 08, 2012 5:34 PM
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Subject: RoHS
 
We have an adhesive with no RoHS certs, Are there RoHS capable test labs in the 
US. I would presume there is some % of total content that is allowed if one 
only knew what materials are in the adhesive. Not my area just asking for a 
panicked compatriot. He’s looking for any means at the moment to clear this gap.
Gary McInturff
Reliability/Compliance Engineer     
 
  
Esterline Interface Technologies Featuring
ADVANCED INPUT, MEMTRON, and LRE MEDICAL products   
600 W. Wilbur Avenue
Coeur d’Alene, ID  83815-9496
Office:208-635-8306
Cell:  509 868 2279
Toll Free: 800-444-5923 X 1238
gary.mcintu...@esterline.com
 
 
www.esterline.com/interfacetechnologies
 
Technology, Innovation, Performance... 
 
 
-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html
Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.
Website: http://www.ieee-pses.org/
Instructions: http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html 
For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell  
For policy questions, send mail to:
Jim Bacher 
David Heald  



LECO Corporation Notice:This communication may contain confidential information 
intended for the named recipient(s) only. If you received this by mistake, 
please destroy it and notify us of the error. Thank you. 
-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html
Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.
Website: http://www.ieee-pses.org/
Instructions: http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html 
For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell  
For policy questions, send mail to:
Jim Bacher 
David Heald  
-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html
Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.
Website: http://www.ieee-pses.org/
Instructions: http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html 
For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell  
For policy questions, send mail to:
Jim Bacher  
David Heald 

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


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

Re: [PSES] RoHS

[Brian Oconnell]

Get used to recurring testing. Think AQL. Have you looked at RoHS
re-castigated?

Brian

-Original Message-
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Kunde, Brian
Sent: Thursday, February 09, 2012 6:36 AM
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Subject: RE: RoHS

Even if you tested the adhesive, since you do not have manufacturing control
and the manufacturer is unable or unwilling to declare their adhesive RoHS
compliant, you will not know if the adhesive will remain RoHS compliant. The
manufacturer could change their adhesive without your knowledge. You would
have to do lot sample testing of your production.

The Other Brian

From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of McInturff,
Gary
Sent: Wednesday, February 08, 2012 5:34 PM
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Subject: RoHS

We have an adhesive with no RoHS certs, Are there RoHS capable test labs in
the US. I would presume there is some % of total content that is allowed if
one only knew what materials are in the adhesive. Not my area just asking
for a panicked compatriot. He's looking for any means at the moment to clear
this gap.
Gary McInturff
Reliability/Compliance Engineer



Esterline Interface TechnologiesFeaturing
ADVANCED INPUT, MEMTRON, and LRE MEDICAL products
600 W. Wilbur Avenue
Coeur d'Alene, ID  83815-9496
Office:208-635-8306
Cell:  509 868 2279
Toll Free: 800-444-5923 X 1238
gary.mcintu...@esterline.com

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


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

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

Website:  http://www.ieee-pses.org/
Instructions:  http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html

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

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] RoHS - an EU view

[Kunde, Brian]

If you have a product who's category falls into an exemption for a few years 
after the 2013 date, do you still have to show the RoHS directive on your DOC 
starting 2013, but somehow state it is compliant via an exemption, or just 
don't mention it until it is required? What is the proper procedure in this 
case?

Thanks,
The Other Brian

From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ron Pickard
Sent: Thursday, February 09, 2012 11:18 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] RoHS - an EU view

To all,
In addition and especially to those that are not yet aware, please note that 
the current RoHS Directive (2002/95/EC) is now in a state of transition to the 
recast RoHS Directive 
(2011/65/EU),
 which will become mandatory on 3-Jan-2013. In a nutshell, the main points of 
this revised directive includes new applied product categories, responsibility 
party definitions/obligations and that the CE marking will then apply, which 
means that by then all declarations of conformity will most likely need to be 
updated to include this directive along with a due diligent establishment of 
conformity.

IHTH.

Best regards,
Ron

From: iun...@servomex.com [mailto:iun...@servomex.com]
Sent: Thursday, February 09, 2012 8:39 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS - an EU view

Group,
Given that the adhesive is unlikely to contain lead, mercury, cadmium, 
hexavalent chromium, the question is: Does it contain either Polybrominated 
biphenyls (PBB), or Polybrominated diphenyl ethers (PBDE) at concentrations 
greater than 0.1% by weight of the homogeneous material? I understand that both 
are flame retardants and used in plastics. Further the need for mandatory EU 
RoHS (2002/95/EC) compliance only kicks in when the adhesive is used in certain 
types of electrical or electronic equipment.

Another issue to be considered as far as the EU and adhesives is associated 
with the impact of the REACH Regulations (1907/2006 (as amended)). Amongst 
other things, these regulations include lists of substances whose use in 
products and their manufacture is either restricted, or requires relevant 
information to be supplied to end users. REACH includes many more substances 
than the six in RoHS, and the restrictions/requirements are not limited to 
electrical and electronic equipment.

Regards

Ian Unwin

From:"Kunde, Brian" 
mailto:brian_ku...@lecotc.com>>
To:EMC-PSTC@LISTSERV.IEEE.ORG
Date:09/02/2012 14:33
Subject:Re: [PSES] RoHS




Even if you tested the adhesive, since you do not have manufacturing control 
and the manufacturer is unable or unwilling to declare their adhesive RoHS 
compliant, you will not know if the adhesive will remain RoHS compliant. The 
manufacturer could change their adhesive without your knowledge. You would have 
to do lot sample testing of your production.

The Other Brian

From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On 
Behalf Of McInturff, Gary
Sent: Wednesday, February 08, 2012 5:34 PM
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Subject: RoHS

We have an adhesive with no RoHS certs, Are there RoHS capable test labs in the 
US. I would presume there is some % of total content that is allowed if one 
only knew what materials are in the adhesive. Not my area just asking for a 
panicked compatriot. He's looking for any means at the moment to clear this gap.
Gary McInturff
Reliability/Compliance Engineer









Esterline Interface Technologies

Featuring
ADVANCED INPUT, MEMTRON, and LRE MEDICAL products



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


www.esterline.com/interfacetechnologies

Technology, Innovation, Performance...






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Re: [PSES] RoHS - an EU view

[Crane, Lauren]

One of the more interesting new Articles in RoHS II is Article 12

 

"Identification of economic operators 

Member States shall ensure that economic operators, on request, identify
the following to the market surveillance authorities, for 10 years
following the placing on the market of the EEE: 

(a) any economic operator who has supplied them with an EEE; 

(b) any economic operator to whom they have supplied an EEE."

 

This also shows up in a slightly different version in the LVD recast
proposal

 

"Identification of economic operators

Economic operators shall, on request, identify the following to the
market surveillance

authorities:

(a) any economic operator who has supplied them with electrical
equipment;

(b) any economic operator to whom they have supplied electrical
equipment.

Economic operators shall be able to present the information referred to
in the first paragraph

for a period of 10 years after they have been supplied with the
electrical equipment and for a

period of 10 years after they have supplied the electrical equipment."

 

This may foreshadow a need for more robust record keeping and possible
threats to business confidential information (who your suppliers are,
and who your customers are), depending on how "on request" is dealt with
(i.e., quarterly reports, or ad hoc for investigations)

 

 

Regards,

Lauren Crane

KLA-Tencor

 

From: Ron Pickard [mailto:rpick...@equinoxpayments.com] 
Sent: Thursday, February 09, 2012 10:18 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS - an EU view

 

To all,

In addition and especially to those that are not yet aware, please note
that the current RoHS Directive (2002/95/EC) is now in a state of
transition to the recast RoHS Directive (2011/65/EU
 ), which will become mandatory on 3-Jan-2013. In a
nutshell, the main points of this revised directive includes new applied
product categories, responsibility party definitions/obligations and
that the CE marking will then apply, which means that by then all
declarations of conformity will most likely need to be updated to
include this directive along with a due diligent establishment of
conformity.

 

IHTH.

 

Best regards,

Ron

 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


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

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

Website:  http://www.ieee-pses.org/
Instructions:  http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html

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

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] RoHS - an EU view

[Ron Pickard]

To all,
In addition and especially to those that are not yet aware, please note that 
the current RoHS Directive (2002/95/EC) is now in a state of transition to the 
recast RoHS Directive 
(2011/65/EU),
 which will become mandatory on 3-Jan-2013. In a nutshell, the main points of 
this revised directive includes new applied product categories, responsibility 
party definitions/obligations and that the CE marking will then apply, which 
means that by then all declarations of conformity will most likely need to be 
updated to include this directive along with a due diligent establishment of 
conformity.

IHTH.

Best regards,
Ron

From: iun...@servomex.com [mailto:iun...@servomex.com]
Sent: Thursday, February 09, 2012 8:39 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS - an EU view

Group,
Given that the adhesive is unlikely to contain lead, mercury, cadmium, 
hexavalent chromium, the question is: Does it contain either Polybrominated 
biphenyls (PBB), or Polybrominated diphenyl ethers (PBDE) at concentrations 
greater than 0.1% by weight of the homogeneous material? I understand that both 
are flame retardants and used in plastics. Further the need for mandatory EU 
RoHS (2002/95/EC) compliance only kicks in when the adhesive is used in certain 
types of electrical or electronic equipment.

Another issue to be considered as far as the EU and adhesives is associated 
with the impact of the REACH Regulations (1907/2006 (as amended)). Amongst 
other things, these regulations include lists of substances whose use in 
products and their manufacture is either restricted, or requires relevant 
information to be supplied to end users. REACH includes many more substances 
than the six in RoHS, and the restrictions/requirements are not limited to 
electrical and electronic equipment.

Regards

Ian Unwin

From:"Kunde, Brian" 
mailto:brian_ku...@lecotc.com>>
To:EMC-PSTC@LISTSERV.IEEE.ORG
Date:09/02/2012 14:33
Subject:Re: [PSES] RoHS




Even if you tested the adhesive, since you do not have manufacturing control 
and the manufacturer is unable or unwilling to declare their adhesive RoHS 
compliant, you will not know if the adhesive will remain RoHS compliant. The 
manufacturer could change their adhesive without your knowledge. You would have 
to do lot sample testing of your production.

The Other Brian

From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On 
Behalf Of McInturff, Gary
Sent: Wednesday, February 08, 2012 5:34 PM
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Subject: RoHS

We have an adhesive with no RoHS certs, Are there RoHS capable test labs in the 
US. I would presume there is some % of total content that is allowed if one 
only knew what materials are in the adhesive. Not my area just asking for a 
panicked compatriot. He's looking for any means at the moment to clear this gap.
Gary McInturff
Reliability/Compliance Engineer









Esterline Interface Technologies

Featuring
ADVANCED INPUT, MEMTRON, and LRE MEDICAL products



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


www.esterline.com/interfacetechnologies

Technology, Innovation, Performance...






 Servomex company information and outgoing e-mail advice. 
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England.
e-mail: i...@servomex.com
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Re: [PSES] RoHS - an EU view

[John Woodgate]

In message 
, 
dated Thu, 9 Feb 2012, iun...@servomex.com writes:


Given that the adhesive is unlikely to contain lead, mercury, cadmium, 
hexavalent chromium,


Any of those except perhaps cadmium, could be in mould and fungus 
inhibitor.

--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
If 'QWERTY' is an English keyboard, what language is 'WYSIWYG' for?

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Re: [PSES] RoHS - an EU view

[IUnwin]

Group,

Given that the adhesive is unlikely
to contain lead, mercury, cadmium, hexavalent chromium, the question is:
Does it contain either Polybrominated biphenyls (PBB), or Polybrominated
diphenyl ethers (PBDE) at concentrations greater than 0.1% by weight of
the homogeneous material? I understand that both are flame retardants and
used in plastics. Further the need for mandatory EU RoHS (2002/95/EC) compliance
only kicks in when the adhesive is used in certain types of electrical
or electronic equipment.

Another issue to be considered as far
as the EU and adhesives is associated with the impact of the REACH Regulations
(1907/2006 (as amended)). Amongst other things, these regulations include
lists of substances whose use in products and their manufacture is either
restricted, or requires relevant information to be supplied to end users.
REACH includes many more substances than the six in RoHS, and the restrictions/requirements
are not limited to electrical and electronic equipment.

Regards

Ian Unwin


From:      
 "Kunde, Brian"

To:      
 EMC-PSTC@LISTSERV.IEEE.ORG
Date:      
 09/02/2012 14:33
Subject:    
   Re: [PSES] RoHS




Even if you tested the adhesive,
since you do not have manufacturing control and the manufacturer is unable
or unwilling to declare their adhesive RoHS compliant, you will not know
if the adhesive will remain RoHS compliant. The manufacturer could change
their adhesive without your knowledge. You would have to do lot sample
testing of your production.
 
The Other Brian
 
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]
On Behalf Of McInturff, Gary
Sent: Wednesday, February 08, 2012 5:34 PM
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Subject: RoHS
 
We have an adhesive with no RoHS certs, Are
there RoHS capable test labs in the US. I would presume there is some %
of total content that is allowed if one only knew what materials are in
the adhesive. Not my area just asking for a panicked compatriot. He’s
looking for any means at the moment to clear this gap.



Gary McInturff
Reliability/Compliance Engineer
 
 
 



 

Esterline Interface Technologies
Featuring
ADVANCED INPUT, MEMTRON,
and LRE MEDICAL products
 

600 W. Wilbur Avenue
Coeur d’Alene, ID  83815-9496
Office:208-635-8306
Cell:  509 868 2279
Toll Free: 800-444-5923 X 1238
gary.mcintu...@esterline.com
 
 
www.esterline.com/interfacetechnologies
 
Technology, Innovation,
Performance...
 



 Servomex company information and outgoing e-mail advice. 
Servomex Group Limited, Jarvis Brook, Crowborough, East Sussex, TN6 3FB,
England.
e-mail: i...@servomex.com 
Company Registered in England: No.2170458 
VAT No.: GB 522 6077 63

EXPORT CONTROL INFORMATION: Resale, onward shipment or diversion of Servomex
products to embargoed destinations including but not limited to Iran, Syria,
Sudan and North Korea is strictly prohibited.

This email has been scanned for all viruses by MessageLabs and contains
information from Servomex which may be privileged or confidential. The
information is intended to be for the use of the individual(s) or entity
named above. If you are not the intended recipient be aware that any disclosure,
copying, distribution or use of the contents of this information is prohibited.
If you have received this electronic message in error, please notify us
immediately. Servomex may, as part of its normal activities, monitor, edit
or censor the content of any information and software, transmitted through,
or stored on, its facilities.
-

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Re: [PSES] RoHS

[James, Chris]

If the mfr will not divulge the make up of the adhesive then switch to
one who will. Any adhesive vendor placing their product into the EU
either directly or indirectly should be cognizant with the requirements
of REACH and almost certainly RoHS.

 

Chris

 

 

 

From: Kunde, Brian [mailto:brian_ku...@lecotc.com] 
Sent: 09 February 2012 14:36
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] RoHS

 

Even if you tested the adhesive, since you do not have manufacturing
control and the manufacturer is unable or unwilling to declare their
adhesive RoHS compliant, you will not know if the adhesive will remain
RoHS compliant. The manufacturer could change their adhesive without
your knowledge. You would have to do lot sample testing of your
production.

 

The Other Brian

 

From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of
McInturff, Gary
Sent: Wednesday, February 08, 2012 5:34 PM
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Subject: RoHS

 

We have an adhesive with no RoHS certs, Are there RoHS capable test labs
in the US. I would presume there is some % of total content that is
allowed if one only knew what materials are in the adhesive. Not my area
just asking for a panicked compatriot. He's looking for any means at the
moment to clear this gap.

Gary McInturff

Reliability/Compliance Engineer

 

 

 

 

Esterline Interface Technologies

Featuring

ADVANCED INPUT, MEMTRON, and LRE MEDICAL products

 

600 W. Wilbur Avenue

Coeur d'Alene, ID  83815-9496

Office:208-635-8306

Cell:  509 868 2279

Toll Free: 800-444-5923 X 1238

gary.mcintu...@esterline.com  

 

 

www.esterline.com/interfacetechnologies
 

 

Technology, Innovation, Performance...

 

 

-


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LECO Corporation Notice: This communication may contain confidential
information intended for the named recipient(s) only. If you received
this by mistake, please destroy it and notify us of the error. Thank
you. 


-


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Re: [PSES] RoHS

[Kunde, Brian]

Even if you tested the adhesive, since you do not have manufacturing control 
and the manufacturer is unable or unwilling to declare their adhesive RoHS 
compliant, you will not know if the adhesive will remain RoHS compliant. The 
manufacturer could change their adhesive without your knowledge. You would have 
to do lot sample testing of your production.

The Other Brian

From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of McInturff, Gary
Sent: Wednesday, February 08, 2012 5:34 PM
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Subject: RoHS

We have an adhesive with no RoHS certs, Are there RoHS capable test labs in the 
US. I would presume there is some % of total content that is allowed if one 
only knew what materials are in the adhesive. Not my area just asking for a 
panicked compatriot. He's looking for any means at the moment to clear this gap.
Gary McInturff
Reliability/Compliance Engineer








Esterline Interface Technologies

Featuring
ADVANCED INPUT, MEMTRON, and LRE MEDICAL products



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


www.esterline.com/interfacetechnologies

Technology, Innovation, Performance...



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information intended for the named recipient(s) only. If you received this by 
mistake, please destroy it and notify us of the error. Thank you.

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Re: [PSES] Melting BNC connectors

[John Woodgate]

In message 
, 
dated Thu, 9 Feb 2012, N.Shani  writes:


Doug, you could do all of us a great service if you mentioned what & 
how the connector was marked, or where it was sourced.
We all take short cuts every so often, so a Buyer Beware with a bit 
more details will be appreciated.


I don't see any great problem in the use of pewter or similar as the 
body of a connector for indoor use. Pewter just goes dull on exposure to 
the air; it does not normally corrode, although alkalis should be 
avoided. In any case, I expect the connector would be nickel-plated.


I didn't find any resistivity data, but tin is about 7 times the 
resistance of copper. However, the current density in connector bodies 
is usually very low.

--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
If 'QWERTY' is an English keyboard, what language is 'WYSIWYG' for?

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Re: [PSES] Melting BNC connectors

[Scott B. Lacey]

The better quality bnc connectors are usually nickel-plated brass. If you 
scrape a small area the brass color will show under bright light. Also, 
many of the cheaper connectors use dielectric material that will soften 
during soldering.

Scott B. Lacey

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Re: [PSES] Melting BNC connectors

[N.Shani]

Doug, you could do all of us a great service if you mentioned what & how
the connector was marked, or where it was sourced.
We all take short cuts every so often, so a Buyer Beware with a bit more
details will be appreciated.

Cheers,
N. Shani
Ottawa, ON

On Thu, Feb 9, 2012 at 00:31, Doug Smith  wrote:

>  Hi Everyone,
>
> I have been traveling and am a few days late on my latest Technical
> Tidbit. Here are the details:
>
> Technical Tidbit - February 2012
> *The Melted BNC Adapter*
>
>  This month's Technical Tidbit describes an unusual side effect of trying
> to use inexpensive BNC hardware.
>
>  *Abstract:* I often solder wires or components to BNC hardware to make
> voltage probes and magnetic loop probes. The process usually goes smoothly,
> except this time. Who would have guessed that the metal portion of BNC
> hardware could melt from the heat of soldering!
>
> The link to the article is: http://emcesd.com/tt2012/tt020812.htm
>
> If you see a "[1]" at the end of the above link placed there by software
> not resident on my computer, you must remove it from the link for the link
> to work. Alternately you can copy the link without the [1] into a browser.
>
> This spring, I will be moving from Los Gatos, CA to Boulder City, NV and
> setting my office up there as well as my residence (phone and Internet
> lines are being installed next week in the office). If you want to see what
> I am up to there, go to http://emcesd.com (near the top of the page)
> where I have posted pictures and information.  Feel free to come for a
> visit and see the Lake Mead National Recreation Area! I will give you a
> personal tour.
>
> Doug
>
> --
> ---
> ___  _   Doug Smith
>  \  / )  P.O. Box 1457
>   =  Los Gatos, CA 95031-1457
>_ / \ / \ _   TEL/FAX: 408-356-4186/358-3799
>  /  /\  \ ] /  /\  \ Mobile:  408-858-4528
> |  q-( )  |  o  |Email:   d...@dsmith.org
>  \ _ /]\ _ / Website: http://www.dsmith.org
> ---
>
>  -
> 
>
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to <
> emc-p...@ieee.org>
>
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>
> Attachments are not permitted but the IEEE PSES Online Communities site at
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> well-used formats), large files, etc.
>
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>
> For help, send mail to the list administrators:
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> Mike Cantwell 
>
> For policy questions, send mail to:
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> David Heald 
>

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Re: [PSES] Melting BNC connectors

[John Woodgate]

In message <07D4FF89DF924FC286DB1C551A1EA11E@LENVOR61iJOHN>, dated Thu, 
9 Feb 2012, John Cotman  writes:



RoHS compliant pewter?


Yes: lead used to be included in lower-grade material but has been 
eliminated from European pewter. From Wikipedia:

QUOTE
Pewter is a malleable metal alloy, traditionally 85–99% tin, with the 
remainder consisting of copper, antimony, bismuth and lead. Copper and 
antimony act as hardeners while lead is common in the lower grades of 
pewter, which have a bluish tint. It has a low melting point, around 
170–230 °C (338–446°F), depending on the exact mixture of 
metals.[1] The word pewter is probably a variation of the word spelter, 
a colloquial name for zinc.[2]

ENDQUOTE

Curiously, there is no zinc in genuine pewter. In fact, tin-zinc as an 
alloy seems to exist only as an electroplating. The molten metals may be 
immiscible.

--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
If 'QWERTY' is an English keyboard, what language is 'WYSIWYG' for?

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Re: [PSES] Melting BNC connectors

[John Cotman]

RoHS compliant pewter?

-Original Message-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk] 
Sent: 09 February 2012 06:36
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Melting BNC connectors

In message <4f335a4b.4000...@emcesd.com>, dated Wed, 8 Feb 2012, Doug 
Smith  writes:

>Who would have guessed that the metal portion of BNC hardware could 
>melt from the heat of soldering!

The body is probably made of pewter - tin with a small amount of other 
metals. 100 years ago, was in fashion for teapots and associated 
vessels. Now not in fashion - yet.
-- 
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
If 'QWERTY' is an English keyboard, what language is 'WYSIWYG' for?

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