Dave,
I think it should be the other way around. Y-caps are used from line to
ground. X-caps are used across the line. The Y class is for applications
where a shorted cap can result in a shock hazard. There are also subclasses
like X1, X2 that correspond to maximum voltage levels.
Dan Kwok
I had a laser printer that flashed all the lights (at about 1 Hz) in my home
office whenever it was switched on. It drove me nuts. When I contacted the
vendor about this issue, I was informed they were not expecting the $400
printer to be used in a home office environment. Imagine that.
Dan
taps that are quickly switched in and out depending on signal power
requirements.
-
Dan Kwok, P.Eng.
Principal Engineer
Electromagnetic Compatibility
Intetron Consulting, Inc.
Ph (604) 432-9874
E-mail dk...@intetron.com
OATS, the usual practice is to
add an extra 6 dB to account for ground plane reflection.
-
Dan Kwok, P.Eng.
Principal Engineer
Electromagnetic Compatibility
Intetron Consulting, Inc.
Ph (604) 432-9874
E-mail dk...@intetron.com
are oriented to be read when the ground
pin is in the uppermost position.
There you have it. Ground pin on top.
-----
Dan Kwok, P.Eng.
Principal Engineer
Electromagnetic Compatibility
Intetron Consulting, Inc.
Ph (604) 432-9874
E-mail
If you meant more than 9000 cycles per second, yes, that would be
classified as a digital device under FCC Part 15. SMPS are not likely to
switch at that frequency. More typically, they switch at rates above 30
kHz, well beyond audio frequencies.
--
--
.
Dan Kwok
Principal Engineer
http://www.intetron.com
---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/
To cancel your subscription, send
http://www.oneac.com/. Click on "Real Life Stories" for some interesting
reading.
Hope this helps.
-----
Dan Kwok, P.Eng.
Principal Engineer
Electromagnetic Compatibility
Intetron Consulting, Inc.
Ph (604) 432-9874
"Collins, Jeffrey" wrote:
>
> Group,
>
> Has anyone had experiences with Type Approvals for telecom equipment in
> China? I'm specifically looking for laws which spell out what type of
> Telecom products require it and what types are exempt.
> I received a request from our sales in China that t
There are probably many good books out there but here are my favorites:
Johnson & Graham
High-Speed Digital Design
A Handbook of Black Magic
Prentice Hall
ISBN 0-13-395724-1
Clayton Paul
Introduction to Electromagnetic Compatibility
Wiley Interscience publication
ISBN 0-471-54927-4
Johnson & Gr
Scott,
Defective cords have been around long before someone got the idea to
manufacture them offshore. How would you be able to tell, without using
the "Hershey" criteria, if a power cord is any good?
Dan Kwok
Scott Lacey wrote:
>
> Jim,
> It seems that some of the &quo
reful.
-----
Dan Kwok, P.Eng.
Principal Engineer
Electromagnetic Compatibility
Intetron Consulting, Inc.
Ph (604) 432-9874
E-mail dk...@intetron.com
Internet http://www.intetron.com
Robert Macy wrote:
>
> It definitely was not supplied by the heater company. It was a high quality
&g
not make it to the store bins.
On the brighter side, speeding up a FET is hard to do. Slowing it down in a
circuit is much easier for EMC purposes.
-----
Dan Kwok, P.Eng.
Principal Engineer
Electromagnetic Compatibility
Intetron Consul
?
-
Dan Kwok, P.Eng.
Principal Engineer
Electromagnetic Compatibility
Intetron Consulting, Inc.
Ph (604) 432-9874
E-mail dk...@intetron.com
Internet http://www.intetron.com
- Original Message -
From: "Robert Macy"
To: "Roman, Dan" ;
Sent: Thursday, Octo
Amund,
NAV Canada, formerly part of Transport Canada, which operates air navigation
services, is a member of RTCA. Transport Canada also adopts RTCA/DO-160 for
equipment aboard aircraft.
-
Dan Kwok, P.Eng.
Principal Engineer
and unsafe
in my estimate.
-----
Dan Kwok, P.Eng.
Principal Engineer
Electromagnetic Compatibility
Intetron Consulting, Inc.
Ph (604) 432-9874
E-mail dk...@intetron.com
Internet http://www.intetron.com
- Original Message -
From:
To: "SEHS Grapevin
Steve:
I don't have a copy of EN60945 with me but there is a host of immunity
issues that come up in a radar environment both from a conducted and
radiated EMI perspective. Most current commercial specs concerning
computer equipment only deal with radiated emissions and immunity up to
one gigaher
Does anyone have an idea on when the cessation date for EN 300-339 will be
once EN 301-498 V1.3.1 becomes harmonized?
- Original Message -
From: "Andrea Bishop"
To:
Sent: Wednesday, October 10, 2001 12:22 AM
Subject: FW: 2 GHz Amplifiers
>
> ETSI EN 301 489-1 V 1.3.1 was formally pub
EN55024 is a product family standard. In this case, the product family
is information technology equipment. EN50082-1 is a generic standard.
Generally speaking, generic standards should be used only when no
specific product family standards apply.
--
umber.
-----
Dan Kwok, P.Eng.
Principal Engineer
Electromagnetic Compatibility
Intetron Consulting, Inc.
Ph (604) 432-9874
E-mail dk...@intetron.com
Internet http://www.intetron.com
- Original Message -
From: "Art Michael"
To:
Cc:
Sent: Wednesday, August 2
"Wismer, Sam" wrote:
>
> According to EN55022:1994, the Class A warning does no prohibit use in a
> domestic(residential) environment, it simply states that if it causes
> interference in that environment, the user may be required to take adequate
> measures.
>
> Domestic environment is describe
Thanks Barbara for the detailed text. It would seem Article 10.5 of the
EMC Directive is no longer relevant when one is applying the RTTE
Directive. That is implied in the wording of Article 20 of the RTTE
Directive. Even though Article 10.5 remains in the text of the EMC
Directive, I anticipate t
John Woodgate wrote:
> 10.5 is deleted in 'favour' of the RTTE Directive, isn't it?
Article 10.5 is still in the current version of the EMC Directive.
Dan Kwok
--
Daniel Kwok, P.Eng.
Prin
>
What happens if a "type-examination certificate" is required under
Article 10.5 of the EMC Directive? Can a U.S. CAB also issue this
certificate or would one need to obtain it from a Notified Body located
in the EU?
Just curious.
Dan Kwok
-
of rules for placing radio
transmitters in Norway, Liechtenstein and Iceland?
Any insights on this would be greatly appreciated.
Dan Kwok
Intetron Consulting Inc.
---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc
So far, harmonised EMC standards seem to be "product centric". But, when
multiple products (boxes) are configured into a system, EMC issues can
still arise. In some cases, EMC problems can result not from the design
of any one individual box, but the the overall interconnection of
multiple boxes t
Dave Heald wrote:
>
> Article 2, Definitions
>
> (c) `radio equipment" means a product, or relevantcomponent thereof,
> capable of communication bymeans of the emission and/or reception of
> radiowaves utilising the spectrum allocated to terrestrial/space
> radiocommunication;
Hi Dave,
The
Kevin Harris wrote:
>
> So the moment has arrived, do you CE mark the device? If you say yes, what
> directive did you apply? If you say no, what is your reasoning?
I guess you can always mark it with a "dummy" CE mark (=:
--
--
wo...@sensormatic.com wrote:
>
> I am trying to determine if a particular device should be safety certified
> under EN 60950 or EN 61010-1. It would be appreciated if someone would
> provide me with the scope of EN 61010-1. Thanks.
>
> Richard Woods
>
Richard,
It seems EN61010-1 is for contr
for
$400 each.
Dan Kwok
- Original Message -
From:
To:
Cc: ;
Sent: Friday, February 02, 2001 5:37 AM
Subject: RE: FCC for PCs
>
> I recall from my days of managing EMC that the FCC does not allow a
> manufacturer to "declare" if an ITE product is Class A or B.
Richard,
Your concern is quite legitimate. A PC is a device that can be easily
brought into a residential home environment by anyone. Based on that, I
would think it should have been tested to Class B limits.
Dan Kwok
wo...@sensormatic.com wrote:
>
> We are purchasing a PC loade
Hello Richard,
The University of Missouri offers an EMC course in video format. The
course is available by itself or as part of their EMC Certificate
Program. For more details, check out
http://www.umr.edu/~conted/courses/EE/EMC/video.htm or contact Dr. Todd
Hubing at Ph: 573-341-6069.
Dan
--
Hello Ralph:
That's a good question. At one time, I pondered the same question
myself. There are obviously plenty of communication systems operating
under 30 MHz. I suppose there are reasons why CISPR or CISPR 22 does not
specify radiated emissions below 30 MHz. I can suggest one possibility.
Per
Hi Jim,
Have you tried Electronic Test Centre in Airdrie, Alberta?
Tel: (403) 912-0037
--
=
Daniel Kwok Vancouver, BC, Canada
Intetron Consulting, Inc. Telephone 604.432.
Hi Keith,
The University of Missouri-Rolla offers courses on EMC. They also offer
an EMC certificate program. See
http://www.umr.edu/~conted/courses/EE/EMC/certprogram.htm.
--
=
Daniel Kwok
Hello Dick Frobner,
If you're considering a medical devices, you may contact Health Canada's
Device Notification Section at (613) 957-1909. They should be able to
point you in the right direction.
Regards,
--
=
Daniel Kwok
the 4-year
curriculum. But then again, what course would they displace to make
allowance for it, electromagnetics- maybe :-/
Dan Kwok
--
=
Daniel Kwok Vancouver, BC, Canada
Intetron Consulting
written both the P.E. and NARTE EMC Engineer exams
and care to comment?
Regards,
Dan Kwok
> "Linstrom, John (IndSys, GEFanuc, CDI)" wrote:
>
> Is there an EMI/EMC equivalent to the PE (professional engineer) or
> CNE (certified network engineer) - and how would one g
ph,
Would that be more appropriately stated as 0.10 sec? Just curious.
Regards,
Dan Kwok
--
=
Daniel Kwok Vancouver, BC, Canada
Intetron Consulting, Inc.
John, thanks for the reference. It gave a good historical perspective.
It would seem the use of dBv (.775 V reference) and dBV (1.0 V
reference) created enough confusion for the pro audio industry to
introduce the new unit dBu. While not an active observer in the pro
audio scene, I would probably
Dave Wilson wrote:
>
> Has anyone come across this unit before? It's referenced in EN55103-2
> (Professional Audio/Video Immunity) for audio frequency common mode immunity
> testing.
>
Hi Dave,
Are you sure it isn't dBvu? If my memory serves me right, the VU is a
volume unit commonly used in p
ilable
or if there are newer versions?
=====
Dan KwokVancouver, BC, Canada
Intetron Consulting, Inc. Telephone 604.432.9874
Email dk..
terms of space and parts but very
effective at lower frequencies.
--
=====
Dan KwokVancouver, BC, Canada
Intetron Consulting, Inc.
s on the specific application,
transient signal and the susceptibility of the equipment you are
protecting. It usually boils down to a trade-off between speed, size,
transient handling capacity and cost.
Hope that helps.
Regards,
Dan
--
=====
igital video and high speed computer peripherals. It's being touted as
the next generation USB. There is a physical description at:
http://www.ecs.com.tw/ecs/chinese/newtech/ie1394.html
Hope this helps.
Regards,
Dan
====
,
Dan Kwok
wolfgang_josenh...@3com.com wrote:
> Dan,
> The speed limit for 56K modem is approx. 53Kb/s due to the digital interface
> encoded signal power limit of -11dBm per the FCC rules.
>
> The actual speed obtained is based upon the noise level, distance from your
> POP
ndwidth Speed Test" and try it out.
--
=========
Dan KwokVancouver, BC, Canada
Intetron Consulting, Inc. Telephone 604.432.9874
Email dk...@intetron.com
"Free EMC
that was not to be...
Regards,
Dan
--
=========
Dan KwokVancouver, BC, Canada
Intetron Consulting, Inc. Telephone 604.432.9874
Email dk...@intetron.com
"Free EMC Ti
Anil Allamaneni wrote:
>
> I dont think this is right. There are times when my modem says data is being
> transferred at 10k/s. So does that mean actual throughput is 10x8 = 80kbps
> from a 56kbps modem ?? Data transfer over an analog line would essentially
> depend on your line and the distance
.
--
===
Dan Kwok Vancouver, BC, Canada
Intetron Consulting, Inc.Telephone 604.432.9874
Email dk...@intetron.com
*FREE* EMC Tips @ our website http://www.intetron.com
.
--
===
Dan Kwok, P.Eng. Vancouver, BC, Canada
Intetron Consulting, Inc.Telephone 604.432.9874
Email dk...@intetron.com
*FREE* EMC Tips @ our website http://www.intetron.com
.
--
===
Dan Kwok Vancouver, BC, Canada
Intetron Consulting, Inc.Telephone 604.432.9874
Email dk...@intetron.com
*FREE* EMC Tips @ our website http://www.intetron.com
ublic health.
Happy holidays!
--
=======
Dan Kwok, P.Eng. Vancouver, BC, Canada
Intetron Consulting, Inc.Telephone 604.432.9874
Email dk...@intetron.com
*FREE
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