Ahah,
Now we must consider what is officially or sufficiently lame; a lameness
coefficient, so to speak.
Have a great weekend all.
-doug
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Tarver,
Peter
Sent: Friday, June 29, 2007 8:24 AM
To: emc-p...@ieee.org
Subject: RE:
Michael,
This has been a very real requirement in California for almost a year. Check
out: CEC-400-2006-002-REV1
http://www.energy.ca.gov/2006publicati
ns/CEC-400-2006-002/CEC-400-2006-002-REV1.PDF
Section 1601 (u) defines your product class:
(u) Power supplies, which are single
Michael:
See Pages 129-130 in California Appliance Efficiency Regulations,
CEC-400-2006-002
Samuel Lifshutz
Manager QA
MRV Communications Inc.
20520 Nordhoff Street
Chatsworth, CA 91311, USA
( (818) 772-6235 x265
7 (818) 772-0576
* slifsh...@mrv.com
Registered by QMI to ISO 9001:2000
Hello all Compliance Wizards.
The issue of certification and marking of Single-Voltage, External AC-DC and
AC-AC power supplies (wall Warts) to a proposed stand-by energy requirement
regulations has recently surfaced. A web search turned up several things -
but left me with more questions than
Hi Peter,
I think the way you read the standard is the most natural reading, but
the final answer isn't really clear from the standard alone. It would
seem that the penalty for the extra volt of peak voltage (from 420 V to
421 V) is double what it should be (0.2 mm vs. 0.1mm).
If you get
From: Tarver, Peter
Sent: Friday, June 29, 2007 12:00 PM
Man, did I mess this up. See my corrections, below.
For an AC MAINS SUPPLY not exceeding 300 V r.m.s. (420 V peak):
b) if the PEAK WORKING VOLTAGE exceeds the peak value of the
AC MAINS SUPPLY voltage, ...
If we have an ac
In message
be3336be85968d49be01e66d6e365b1e02091...@sjc1amfpew01.am.sanm.corp,
dated Fri, 29 Jun 2007, Tarver, Peter peter.tar...@sanmina-sci.com
writes:
From: John Woodgate
Sent: Thursday, June 28, 2007 2:35 PM
After the London bombings the cell-phone networks overloaded
and either
From: Aldous, Scott
Sent: Friday, June 29, 2007 9:48 AM
Looking over the two versions of the standard, I can see that you're
correctly interpreting the 1st ed., but the 2nd ed. text changed things
all over the place in the insulation area. I don't know if that was
MT2's intent, but that's
Thanks Peter for your comments. Mine interspersed below.
Scott Aldous
Compliance Engineer
Advanced Energy
Tel: 970-407-6872
Fax: 970-407-5872
I wonder what peak working voltage should be used in table 2K
- the actual peak voltage or the peak voltage based on the
mains rms voltage?
From: Brian O'Connell
Sent: Friday, June 29, 2007 7:28 AM
The limitation to the application of Mr. Woodgate's basic
truth is that few western companies consider participation in
standards development an investment; mostly because the
time and money for a non-core engineering activity is
From: Aldous, Scott
Sent: Friday, June 29, 2007 8:56 AM
Bummer - I was referring to an older version of the IEC
standard (60950-1:2001).
I kinda thought something like that. With the 2nd ed of IEC 60950-1, the
clearance and creepage distances went through a huge rewrite.
I wonder what
Bummer - I was referring to an older version of the IEC standard
(60950-1:2001). Everyone, please ignore my previous post (just when you
get comfortable with a standard, they go and change it!). I assumed
secondary circuit because of the table number (per the old standard).
Now, looking at the
From: John Woodgate
Sent: Thursday, June 28, 2007 2:35 PM
After the London bombings the cell-phone networks overloaded
and either collapsed or were shut down by the authorities.
For consumer use or simply limited to EMS use?
After the Loma Prieta earthquake in 1989, all wire line services
Good morning, Scott.
From: Aldous, Scott
Sent: Friday, June 29, 2007 8:18 AM
Table 2L is for minimum creepage distances, not clearance.
I don't know which version of EN 60950-1 you're referring to, but in the
2006 version, Table 2L most certainly applies to clearances.
I see nothing in
Brian,
I hope things are not that grim for you. We would hate to loose a
Brian on here.
In addition to the points you made, can you believe the job descriptions
that are posted on here? In the good-ol-days, you could be an EMC expert
or Safety or Telecom, but today you are expected to be experts
From: Nick Williams
Sent: Friday, June 29, 2007 5:21 AM
Compare the two scenarios...
1. Say mains is 230V, i.e. below 300V so add clearances from
Table 2K
and 2L. Say peak working voltage is 840V. Clearance is 6.4+1.2=7.6mm
From Table 2K, for a 840 Vpk working voltage across some bit
Table 2L is for minimum creepage distances, not clearance. I see
nothing in 60950-1 that indicates values from table 2L are to be added
to values from table 2K for clearances in secondary circuits.
Assuming (as 60950-1 does) that the overvoltage category of the product
is II, then:
Scenario 1
Mr. Woodgate's point is, of course, a basic truth.
But there are other 'basic' truths to corporate life; i.e., what a North
American company will tolerate in terms of resource
allocation/consumption. So if a non-core engineering or support activity
consumes more than a 'minimal' portion of time
From: Powell, Doug
Sent: Thursday, June 28, 2007 4:09 PM
Why do they call it a dead short. I've found very little
help except for a couple of really lame definitions:
How can one navigate by dead reckoning?
How can a battery be dead, if it's not life as we know it, Jim?
Even though
Hi Nick,
As I see it the clearance would be calculated as follows;
Scenario 1
Mains voltage = 230V (mains transient voltage is 2500V) giving a
clearance of 4.0 mm (table 2K) for reinforced, plus the additional
clearance of table 2L for a PWV of 840V which would be 1.2 mm (ignoring
Gentlemen, and ladies, of course...
Our company is providing LED Key Fob torches as good will gifts to the
customers install engineers. We have to take so much care with the product
with RoHS, REACH, CE Marking, FDA, UL, CSA etc. etc. , that these almost
slipped under the net.
Can any one tell
I've been asked the following question by a client:
Compare the two scenarios...
1. Say mains is 230V, i.e. below 300V so add clearances from Table
2K and 2L. Say peak working voltage is 840V. Clearance is
6.4+1.2=7.6mm
2. Say mains is 400V, i.e above 300V so minimum CLEARANCES are
determined
Saw this opening in the local area, thought I would post it here.
http://jobview.monster.com/getjob.asp?JobID=57021737
http://jobview.monster.com/getjob.asp?
obID=57021737aid=21547900-2967WT.mc_n=MKT000125
aid=21547900-2967WT.mc_n=MKT000125
Bob Richards, NCT.
-
We use the term dead short to distinguish this type of short circuit from one
we refer to as a soft short in our FMEAs.
I first came across the term soft short some 7 years ago working on a DFMEA
with a customer and have since discovered
it is a fairly common term in bridge topology design
Your colonial conjecture is so amusing :) try looking in the OED where dead =
complete, exact, abrupt, absolute, so giving us all these terms:
dead level
dead end
dead drunk
dead centre
dead heat (an exact tie in a race that is)
dead stop
dead calm
dead loss
dead asleep
dead easy
dead on
In message
09c2d42ff0bfca4b829cdbe89b8f66ffe87...@g3w0637.americas.hpqcorp.net,
dated Thu, 28 Jun 2007, Conway, Patrick R (Houston) p.con...@hp.com
writes:
A) Margin at certification time has no intrinsic value.
A certificate granted with 0.5 dB margin is just as
valid
as one
In message 781944.17329...@web39602.mail.mud.yahoo.com, dated Thu, 28
Jun 2007, Bill Owsley wdows...@yahoo.com writes:
Why o why can't we have standards that cover every possibility we can
think of???
Do you or your employer have the time and money to help write them? We
get the standards
Hi Doug:
Here are some definitions from surfing the web...
Short circuit having zero resistance.
I mean short circuit or the TV/Video doesn't work (dead).
A dead short is one that stays connected because we have not
found the problem yet, therefore we have not cleared the
28 matches
Mail list logo
