Hi Richard:
The original question was in regard of
rating markings for a product with
two power inputs. I really didn't want
to expand the discussion to ALL of the
safety issues related to multiple power
inputs -- because all of the other issues
had not been raised by the original
Hi Rich,
I did contemplate including some comments about regular users of the
equipment, but chose not to for reasons of simplicity. Well now I can
say what I was going to say...
Equipment should be designed so that it can be operated safely by staff
who typically have little or no
Take a look at MIL-STD-202G, it's an old but basic standard for testing
components. The ASSIST web site has a new URL:
http://assist.daps.dla.mil/online/start/
There's also MIL-STD-810F
Happy new year!
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org
Hello Gary,
Try using this service, it’s free… and so are some of the standards.
http://assist.daps.dla.mil/quicksearch/
http://assist.daps.dla.mil/quicksearch/
Hope it helps,
David Cereceres
Product Safety Engineer
Pelco
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p
1) I believe that mil-specs for the US have been privatized but I'm not sure
of who is maintaining and updating them. I assume its more than just one of
the document re-sellers such as Global Engineering etc, but clueless as to
whom else it would be. Can someone direct me.
2) I want to develop
It seems to me that dependent on the design of the product, it may also need
a warning label stating that the unit has multiple power sources. You may
need to include wording about the multiple power sources in the user and
service manual.
Jim
Jim Bacher, Senior Engineer
Paxar Americas, Inc.
tiny looking diodes and have wondered how they survive. Could be a thermistor
of a few ohms?
Dave Cuthbert
Micron Technology
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Bill Flanigan
Sent: Monday, December 29, 2003 1:47 PM
To: emc-p
Hello Zhang Guoqing:
You ask how to mark a product that has two sets
of power input terminals, one as the main input
and one as a backup input.
Each input, main and backup, should be separately
marked near the physical connection of each input.
Each marking would be the input for that
Surge limitations in a diode are limited by the ability to transport heat
away from the junction. Heat transport is by diffusion. Because of this
diffusion transport, a good rule of thumb is to scale the peak current
inversely proportional to the square root of the duration of the event.
Fellow compliance wonks...
How to specify a diode bridge to ensure its success during IEC 61000-4-5
Surge testing (mains) to Class 3 (1kV L-L, 2kV L-G)? If the diode spec
declares a maximum peak forward surge current, how do I calculate the
current this immunity test is likely to provide? Any
Hi Ton:
The product is supplied with a DC power adapter
which is current limited, provides overload and
short circuit protection and is specified to accept
an overload or short circuit condition continuously.
This description indicates the DC power adapter is
adequately
Dear Kim,
We can perform pre-tests as well as full compliance tests on analogue and
digital TTE equipment for Europe(RTTE); USA(ACTA): JAPAN; Canada; and South
Africa.
Please take a look at our website www.telefication.com, or contact me directly
at +31 651 18 2400
With kind regards,
Henry
Hi all
1) Does anyone know of a test lab who can make simple functionality test on
analogue tele-products (incl. worst case line condition, noise, voltage
etc.) It is not approvals, but simple test of fare-east cheap products.
2) Alternative, could any one help me building a test set-up for
If you use a wall wart (AC/DC adapters).
AFAIK there is a requirement for the AC/DC adapters to be certified for
safety (PSE mark, Denan process).
Just my 2 ¢.
Tim Foo
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Visit our web
No, but the 12V power supply must be approved, and the TCO or fuse in the
power supply must have the T mark.
Let me add this remark: I was told (by people that I trusted) not to apply
for the approval for a power supply made by a vendor that did not have the
necessary Japanese approval in place
Hi Group,
I had a product which is a Automatic Label Dispenser which rated 12V DC
2A. Could anyone please advice if such product fall under any of the
Japan regulatory requirement, such as DENAN law? Thanks.
Best Regards,
Peck Hoon
This message is from the IEEE EMC Society Product
Ton,
The short answer to your question is that there is no magic formula, rule of
thumb, etc that will match a load having unspecified characteristics to an
over-current protective device, nor to a power source - if the intent is to
select a source closely matched to the load.
I suggest that you
I read in !emc-pstc that Ton Bouw pa0...@mubo.nl wrote (in 001001c3ca
fb$686cf900$fd00a8c0@opticonhlm5183) about 'Rating of a power adapter'
on Thu, 25 Dec 2003:
I have a question for products which an external DC power adapter.
The product is supplied with a DC power adapter which is current
Ton Bouw wrote:
Assuming that the rated current for a product is 1.0A, and assuming that
the fuse rating is determined at 1.5A, then a rating of the power adapter
of
anything over 1.0A would seem to be sufficient for operation and
protection.
However if the rating of the power adapter does not
Hello Group,
I have a question for products which an external DC power adapter.
The product is supplied with a DC power adapter which is current limited,
provides overload and short circuit protection and is specified to accept an
overload or short circuit condition continuously.
Assuming that
I read in !emc-pstc that Bruce T arpanet...@yahoo.com wrote (in
20031224215919.93880.qm...@web60204.mail.yahoo.com) about 'audio/video
EMC standards ?' on Wed, 24 Dec 2003:
looking to know of EMC standards for professional audio/video equipment.
May also include features like MPEG, and XLR
Hi,
looking to know of EMC standards for professional audio/video equipment.
May also include features like MPEG, and XLR connections.
thanks
_
Do you Yahoo!?
Yahoo! Photos - Get your photo on the big screen in Times Square
http://us.rd.yahoo.com/evt=21486/*http
Logically then eu-nuch means Pleasing - what???!
Merry Christmas one and all.
Gary
From: don_borow...@selinc.com [mailto:don_borow...@selinc.com]
Sent: Wednesday, December 24, 2003 9:10 AM
To: emc-p...@majordomo.ieee.org
Subject: RE: Use of Declaration of Conformity (was CE declaration)
I couldn't find the word in any of the dictionaries I looked at, either.
However its meaning is easily discovered. Just as eu-phonic is a sound that
pleases, eu-chronic would be a time that pleases.
Don Borowski
Schwetizer Engineering Labs
Pullman, WA
I read in !emc-pstc that John Jankowski john_jankow...@cnt.com wrote
(in 4EFDC72868C9E64AA474B915D00CE1C40835F3@esnj02) about 'IEC60950-1:
compliance of LEDs' on Wed, 24 Dec 2003:
LED's and panel displays were introduced into the International Standard
IEC-60825, Safety of Laser Products,
I read in !emc-pstc that Bill Flanigan bflani...@ameritherm.com wrote
(in FB6565868403D511952800D0B78483C49EB165@AMERITHERM_PDC) about 'Use
of Declaration of Conformity (was CE declaration)' on Wed, 24 Dec 2003:
Cannot find applicable definition standard for euchronic.
I think I inadvertently
Another word-lurk;
Cannot find applicable definition standard for euchronic.
Do you mean euphonic?
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: Wednesday, December 24, 2003 10:48 AM
To: emc-p...@majordomo.ieee.org
Subject: Re: Use of Declaration of Conformity (was CE declaration)
Kris,
LED's and panel displays were introduced into the International Standard
IEC-60825, Safety of Laser Products, several years ago for just the reasons
you have mentioned.
After the introduction of solid state lasers, it was apparent that the
similarities
in manufacturing/operation of
I read in !emc-pstc that richhug...@aol.com wrote (in 1a9.1e63929a.2d1a
e...@aol.com) about 'Use of Declaration of Conformity (was CE
declaration)' on Wed, 24 Dec 2003:
So, once again, Merry Christmas or Season's Greetings as applicable to you,
Your euchronic felicitations are cordially
Kristiaan,
I would recommend asking the LED manufacturers to supply information in
accordance with Annex G to IEC 60825-1 (Information to be provided by
manufacturers of LEDs ).
Please also be aware that if the LEDs are closely spaced together then you
need to consider the combined radiation
Brian, Please see comments below. Christmas wishes to you too. Richard Hughes
In a message dated 24/12/2003 14:23:49 GMT Standard Time,
boconn...@t-yuden.com writes:
Will this new IEC std harmonize D of C and CE marking requirements among all
of the other directives ?
REH These documents
Mr Hughes
Will this new IEC std harmonize D of C and CE marking requirements among all
of the other directives ?
Will the basis for presumption of conformity change for the current LVD and
EMCD ?
happy holidays,
Brian
-Original Message-
From: richhug...@aol.com [
Hi group,
What information should be provided by the LED manufacturer to show that
panel indicating LED's comply with IEC60950-1, clause 4.3.13.5.?
I raise this question because panel light LED's are having a very high
brightness nowadays.
Vriendelijke Groeten, Best regards, Meilleures
Gert, John,
Before I start into the technicalities I should like to wish everybody on this
forum a very Merry Christmas (or Season's Greetings if you do not celebrate
Christmas) and a safe and happy New Year.
Now to the technicalities...
This discussion has migrated into a debate on legal
for the authorities.
- A DoC has no function between you and your customers.
- I advise to use a civil contract to rule any ce related obligations
and liabilities with your customers.
Gert Gremmen
ce-test, qualified testing
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org
Bill
There are currently 2 routes - not 3!
Currently the Technical Construction File has to be approved by a Competent
Body (= Notified Body)
Therefore you can self-declare against Harmonised Standards but not against
a TCF.
Only when the SLIM version of the Directive comes into force (date
testing
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of iun...@servomex.com
Sent: maandag 22 december 2003 10:13
To: emc-p...@majordomo.ieee.org
Subject: CE declaration
Dear colleagues with knowledge of matters CE,
As I see it there are two methods
I read in !emc-pstc that Bill Flanigan bflani...@ameritherm.com wrote
(in FB6565868403D511952800D0B78483C49EB107@AMERITHERM_PDC) about 'Any
recent changes to assessment rules?' on Tue, 23 Dec 2003:
Have there recently been any changes in the methods of EMC conformity
assessment (per EU
This is a multi-part message in MIME format.
Best Regards
Charles Grasso
Senior Compliance Engineer
Echostar Communications Corp.
Tel: 303-706-5467
Fax: 303-799-6222
Cell: 303-204-2974
Email: charles.gra...@echostar.com; mailto:charles.gra...@echostar.com;
Email Alternate:
to use a civil contract to rule any ce related obligations
and liabilities with your customers.
Gert Gremmen
ce-test, qualified testing
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of iun...@servomex.com
Sent: maandag 22 december 2003 10:13
To: emc
Fellow compliance-wonks,
Have there recently been any changes in the methods of EMC conformity
assessment (per EU Directives)? At
http://europa.eu.int/comm/enterprise/electr_equipment/emc/index.htm
I see the familiar 1) self-declaration, 2)Tech Construction File and 3)
Notified Body. Have there
List members, here is some one looking for a job. If you know of anything
please reply directly to him at: pksee...@umr.edu
From: Prabhanjan Seelam [mailto:pksee...@umr.edu]
Sent: Thursday, December 11, 2003 1:32 AM
To: j.bac...@ieee.org
Subject: Candidate Profile (EMI/EMC/SI/PCB Engineer)
At the risk of incrring the ire of Kim Newman..
Would the members of the RMCEMC contact me directly and I will contact Kim. I
have four excellent speakers already set to present and would like to
minimize confusion.
Thanks
Chas
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p
I read in !emc-pstc that iun...@servomex.com wrote (in OFBBD993EC.1799B
151-on80256e04.0031a...@servomex.co.uk) about 'CE declaration' on Mon,
22 Dec 2003:
Can any CE marking wizards advise me which of these (if any) is the legal
approach? If a), are we obliged to present the information to the
Dear colleagues with knowledge of matters CE,
As I see it there are two methods of declaring CE compliance:
a) Prepare a single CE marking declaration document that lists all the
relevant directives and the standards used to show compliance.
OR
b) Prepare a series of separate declaration
Greetings All,
The IEEE Denver Section in collaboration with the Rocky Mountain Manufacturing
Design Expo, presents a Technical Conference: Innovative Technology
Development in the Rockies.
For those who are interested in presenting a paper, workshop, experiment
and/or demonstration, please
John Woodgate noted
A lever might be that you will only call up ferrites that conform to the
standard, i.e. Japanese, Chinese and Taiwanese products. (;-)
Yes, absent a NEMA ferrite that's how it works; everyone selling the same
product against each other. When you explain to a manufacturer
I read in !emc-pstc that Cortland Richmond 72146@compuserve.com
wrote (in 200312200105_mc3-1-6176-a...@compuserve.com) about
'Standardizing Ferrites' on Sat, 20 Dec 2003:
Ed Price wished:
I sure wish that ferrite manufacturers had a color-code system like you
have
for resistors. Sure, some
Ed Price wished:
I sure wish that ferrite manufacturers had a color-code system like you
have
for resistors. Sure, some of those beads chips are darn small, but I
wonder if even high-volume parts might be markable with some kind of
laser-etched bar-code. (Reading that bar code might be another
I read in !emc-pstc that Ralph McDiarmid ralph.mcdiar...@xantrex.com
wrote (in 67C475A5ECE7D4118AEC0002B325CAB60581A5EF@BCMAIL1) about
'CISPR 25 Conducted Emissions (Current Method)' on Fri, 19 Dec 2003:
In terms of power change in the system as a fuction of resistance (or scalor
of impedance),
In terms of power change in the system as a fuction of resistance (or scalor
of impedance), then I expect it should be 10logR dB(Ohms)
Why not use dB(ohms) if dB(V) is considered a valid unit?
Ralph McDiarmid, AScT
Compliance Engineering Group
Xantrex Technology Inc.
From: John Woodgate
Chris' suggestion of measuring the CM current on the cable sounds like the
simplest and the most direct method. Reducing the EMI really comes down to
reducing the CM current at your frequency of interest.
I have done measurements of type 43 and 77 ferrite material and was surprised
by how lossy
by a few dB by
changing R and X while holding |Z| constant. So, I would say that substituting
a bead with a higher |Z|, or even the same |Z|, but with a different mix of R
and X could increase emissions (or lower emissions).
Dave Cuthbert
Micron Technology
From: owner-emc-p
Charles,
Sometimes, I wish I was a “lurker” and I could just keep my big keyboard
shut. But I can’t so….
I can tell that my previous sarcasm may not be welcome. My apologies. I will
readily admit that others have provided you excellent information regarding
how to perform this
Well Chris - There is a long story attached to this requirement. Let me
summarize:
1. We manufacture a significant number of settopboxes for satellite TV. I
hesitate
to put actual numbers in public - lets just say a sh*t load. Cost therefore is
paramount...as you can appreciate.
Mulitple vendors
You'll need to get a copy of IEC (or EN) 61000-4-5 which shows how the test is
done.
You're correct about the coupling -- line to PE for I/O lines, but NOT
coupled via an inductive clamp. You'll need some kind of coupler/decoupler
appropriate to the line your testing. For most I/O lines with
I should point out that the energy absorbed per bead is reduced by a factor of
4. The total energy absorbed by the beads is reduced by a factor of 2. Follow
the current.
Dave -Original Message-
From: drcuthbert
Sent: Friday, December 19, 2003 8:40 AM
To: 'Ken Javor'; Price, Ed; 'Grasso,
, we have a
reduction in radiated energy yet the beads are absorbing less RF energy
themselves.
Dave Cuthbert
Micron Technology
-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Ken Javor
Sent: Thursday, December 18
...@acstestlab.com
Sam Wismer swis...@acstestlab.com
Sent by: owner-emc-p...@majordomo.ieee.org
12/19/2003 09:37 AM
Please respond to Sam Wismer
To: EMC 2 emc-p...@majordomo.ieee.org
cc:
Subject: Surge on signal lines
Hello All,
I have a product in which
about what part was used.
Just my $0.02..
Michael Sundstrom
NOKIA
TCC Dallas / EMC
ofc: (972) 374-1462
cell: (817) 917-5021
amateur call: KB5UKT
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of ext Price, Ed
Sent: 19
Works for me.
From: John Woodgate j...@jmwa.demon.co.uk
Reply-To: John Woodgate j...@jmwa.demon.co.uk
Date: Fri, 19 Dec 2003 13:29:14 +
To: emc-p...@majordomo.ieee.org
Subject: Re: CISPR 25 Conducted Emissions (Current Method)
I read in !emc-pstc that Ken Javor
For myself, I have found it a whole lot less confusing to work in voltage
and current as linear units, then at the end converting back to dB if
necessary.
Don Borowski
Schweitzer Engineering Labs
Pullman, WA
Ken Javor ken.ja...@emccompliance.com wrote on 12/18/2003 05:22:55 PM:
It is
-Original Message-
From: Chris Maxwell [ mailto:chris.maxw...@nettest.com]
Sent: Friday, December 19, 2003 6:29 AM
To: Ken Javor; Price, Ed; Grasso, Charles; emc-p...@majordomo.ieee.org
Subject: RE: Measuring a ferrite performance
As usual, this thread has been very educational,
Hello All,
I have a product in which the customers can envision the user to use a signal
cable longer than 30m. He has no control over what is used and the product
will function with a cable of that length. The standard I am testing to is EN
61000-6-2.
The requirement for signal lines says
As usual, this thread has been very educational, the mere asking of the
question has unleashed many answers, from which I have gained in my own
knowledge. The most practical question that I would ask is:
Why the h___ would your component engineering group want you to measure the
impedance of
I read in !emc-pstc that Cortland Richmond 72146@compuserve.com
wrote (in 200312181715_mc3-1-6123-8...@compuserve.com) about
'Measuring a ferrite performance' on Thu, 18 Dec 2003:
This of course does not tell you the
impedance of beads, only attenuation in the fixture, or one the cord,
but
I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote
(in bc07af0f.88f0%ken.ja...@emccompliance.com) about 'CISPR 25
Conducted Emissions (Current Method)' on Thu, 18 Dec 2003:
It is true that the unit dB Ohm has to be interpreted in context.
However that does not change its
I read in !emc-pstc that Price, Ed ed.pr...@cubic.com wrote (in
b78135310217d511907c0090273f5190d0c...@curly.ds.cubic.com) about
'Measuring a ferrite performance' on Thu, 18 Dec 2003:
2. Decide on system impedance. If 50 ohms is OK, then just connect
a 3 dB attenuator to each of the
On Fri, 19 Dec 2003 12:26:48 +0800,
Peck Hoon CHON (HPI-MY) peckhoon.c...@my.hpi-group.com wrote:
Recently we had a product which are required to enter into Japan market.
...
Motor-operated Product is referred to the AC electric appliances. (with
selection of single or three phase, etc)
Dear group,
Recently we had a product which are required to enter into Japan market.
There are procedures called for the importer to make a report of
business to the Minister of Economy, Trade and Industry. The report
shall include a classification of electrical appliances (Article 2) and
Type
As usual, Ed's advice is practical and economical to implement. I would add
the following to make it more comprehensive. Ed's test measures insertion
loss. You can calculate impedance from that.
At frequencies where the impedance is high Ed's test works well. At
frequencies where the
A major error was made in that attachment. The transfer impedance of a
current probe is not a loss. It is a conversion factor. Current passing
through the window yields a potential at the probe output, when loaded by
its proper termination impedance, typically 50 Ohms, or 34 dB Ohms. That is
It is true that the unit dB Ohm has to be interpreted in context. However
that does not change its utility. Current probe transfer impedance and
shielding transfer impedance both have units of dB Ohm. What would be a
better substitute?
From: John Woodgate j...@jmwa.demon.co.uk
Reply-To:
Charles Grasso asked,
I have a requirement to test the performance of ferrite bead (one that
that can fit over a power cord) to 500MHz for qualification of alternate
vendors.
I have an impedance analyser - but it only goes to 40MHz. Does anyone have
a good way to verify ferrite impedance.??
. Good vendors can control the impedance within +/- 20%.
Some can be off to +/- 40%.
Hope this helps.
Minjia Xu ( Catherine)
EMC Engineer , Ph.D
Hardware Test Regulations
All-in-One Personal Printing - HP
c...@sdd.hp.com
From: owner-emc-p
I read in !emc-pstc that scott@jci.com wrote (in
of227b3f0b.4367e65e-on85256e00.0056b9fa-85256e00.0056d...@jci.com)
about 'CISPR 25 Conducted Emissions (Current Method)' on Thu, 18 Dec
2003:
Please read the attached document that he assembled for the details.
Not relevant to the question,
Greetings All,
I believe the NEBS Criteria Levels is from SR-3580, not SR-5270.
Regards,
Richard
=
Richard Georgerian
Compliance Engineer
Carrier Access Corporation
5395 Pearl Parkway
Boulder, CO 80301
USA
Tele: 303-218-5748 Fax: 303-218-5503
This is indeed the textbook description of NEBS levels, and probably was
extracted out of SR-5270 (I think - somebody else might want to correct
that). That is only part of the story however. Each of the RBOC's defines
what tests they require before it meets their own definition of level 1, 2
or
Don't buy a 500 MHz analyzer. You'll end up having an analyzer that still
won't be what you may need. Rent it for the ferrite test, and later buy a
decent network analyzer :) It is possible to find decent used equipment that
isn't terribly expensive (in relative terms) these days.
Neven
At
Don't buy a 500 MHz analyzer. You'll end up having an analyzer that still
won't be what you may need. Rent it for the ferrite test, and later buy a
decent network analyzer :) It is possible to find decent used equipment that
isn't terribly expensive (in relative terms) these days.
Neven
At
Thanks for the responses.
The component engineering group are asking for impedance
vs freq so that they can compare the graphs to the specs.
I was thinking of using a network analyser...
Best Regards
Charles Grasso
Senior Compliance Engineer
Echostar Communications Corp.
Tel: 303-706-5467
HI Chas,
I have a Network analyser that will go to 500 MHz...
Derek.
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Visit our web site at: http://www.ieee-pses.org/
To cancel your subscription, send mail to:
majord...@ieee.org
Ed,
Steward ferrite discusses this question their website. Other than noting
it was there I didn't read it so I can't speak to the quality of the article,
but one would assume these guys should know how to make such a measurement.
Gary
From: Price, Ed [mailto:ed.pr...@cubic.com]
Sent:
Charles,
You can do the same thing that ED PRICE suggested if your spectrum analyzer
has a tracking generator option installed. Just replace the signal
generator by the tracking generator.
We have characterized ferrite clamps and such in the same manner.
Best Regards,
Scott Mee
Johnson
Low cost method: An MFJ (mfj enterprises) MFJ-269B impedance analyzer covers
1.7-170 MHz and 420-450 MHz. It will give you the R and X up to 600 ohms.
Price is about $370. A very useful item to have around the lab.
Dave Cuthbert
Micron Technology
From: owner-emc-p...@majordomo.ieee.org
-Original Message-
From: Grasso, Charles [ mailto:charles.gra...@echostar.com]
Sent: Thursday, December 18, 2003 9:40 AM
To: 'emc-p...@majordomo.ieee.org'
Subject: Measuring a ferrite performance
Greetings all:
I have a requirement to test the performance of ferrite bead (one
That is the formula for the geometric sum of 2 RMS quantities. For example,
if you have a primary circuit that has a working voltage of 230Vrms and a
secondary circuit with a working voltage of 32Vdc, the RMS working voltage
BETWEEN the two circuits is determined with the formula, giving you
At the risk of collecting the ire of the instrument
manufacturers, look at buying an up to 500MHz network
analyzer. Do an in house demonstration.
- Robert -
Robert A. Macy, PE .. m...@california.com
408 286 3985 . . . .. . . fx 408 297 9121
AJM International
Brian,
That is the rms value of two uncorrelated ac voltage
sources.
For noise, this is the way uncorrelated noise power adds.
- Robert -
Robert A. Macy, PE .. m...@california.com
408 286 3985 . . . .. . . fx 408 297 9121
AJM International Electronics
Art
Thanks for that.
Four points:
1) Slight error in your URL, should be
http://www.cbscheme.org/ctl/decisions.htm
2)This an IEC CB site, not an EU/CENELEC site, so the official validity of
anything stated thereup-on is questionable.
3) Yes, these also give the OSM decision sheets, but
Greetings all:
I have a requirement to test the performance of ferrite bead (one that
that can fit over a power cord) to 500MHz for qualification of
alternate vendors.
I have an impedance analyser - but it only goes to 40MHz. Does anyone
have a good way to verify ferrite impedance.??
Trevor,
Please check out www.nebs-faq.com for answers to common NEBS questions.
Best regards,
Dave
www.lorusso.com
Trevor Chainey tchai...@telesoft-technologies.com wrote:
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I don't know about voltage, but in maths it is the hypotenuse of a
right-angled triangle!
Regards,
Neil Helsby
Original Message dated 18/12/2003, 15:50:17
Author: Brian O'Connell boconn...@t-yuden.com
Re: :
Good People
What is the basis of this formula for working voltage ?
sqroot(a^2 +
Sorry, the second line was missed from my earlier reply.
I don't know about voltage, but in maths it is the hypotenuse of a
right-angled triangle!
I therefore presume it is the measured voltage calculated from knowing
the active and reactive components of the voltage.
Regards,
Neil Helsby
I read in !emc-pstc that Brian O'Connell boconn...@t-yuden.com wrote
(in f7e9180f6f7f5840858d3db815e4f7ad1f2...@cms21.t-yuden.com) about ''
on Thu, 18 Dec 2003:
Good People
What is the basis of this formula for working voltage ?
sqroot(a^2 + b^2)
It the HIPOTenuse? (;-)
Or
I read in !emc-pstc that Ing. Gert Gremmen g.grem...@cetest.nl wrote
(in mpeeiccjhhndekobpnnbgecidiaa.g.grem...@cetest.nl) about 'CTL
Decisions - the situation for Europe' on Thu, 18 Dec 2003:
CTL decisions are not relevant within the EC compliance system.
Whether a manufacturer
Hello All,
I believe it was mentioned previously, but the link for the CTL
Decisions may have gone unoticed by some;
Both the CTL Decision Sheets and the OSM Decision Sheets are available
online at: http://www.cbscheme.org/ct/decisions.htm
At this same location, there is also a description of
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All,
One of my colleagues in town has a question that he would like to post
here, hoping to find an answer. If you have any thoughts, comments, or
suggestions please reply with them, and I will forward them to him. Also,
feel free to email Pete
Good People
What is the basis of this formula for working voltage ?
sqroot(a^2 + b^2)
thanks,
Brian
Hi Trevor,
The NEBS levels are functionally defined as:
* NEBS Level 1; the min acceptable level of environmental
compatibility needed to preclude hazards and degradation of the network
facility and hazards to personnel. Possible applications for Level 1
criteria include prototype
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