On Fri, 6 Sep 2002 16:19:52 +0900,
Michael Jang mich...@certitek.com wrote:
I have a question for Discharge of capacitors in the primary circuit'
(Related to 60950 standard)
Standard
Equipment is considered to comply if any capacitor
Alan,
You will find that 61000-4-3 only gives you the test method and some suggested
test levels. You don't test to any of the 61000-4 series, you test to
whichever standard calls them up, for example EN 50081,50082, the generic
standards, or EN 55024, ITE immunity. These standards call up
John
By the wider issue I was referring to your assertion that The EMC
Guidelines document explains that having no active components is NOT grounds
for exemption from the EMC Directive.
If this were the case then it would have far reaching implications for many
industries since all
Hi Charles, Warren
Seems that a few of us know what DOES happen and the longterm results, but
quite a few others don't believe that it does - and that even it does then
it is not very important.
The difference between reality and theory!
I suggest that the non-believers try it for themselves
Doesn't sound like you're missing anything. We are just talking about
different things. Common disease, here! Certainly, for the same directive
gain, the aperture of an antenna is smaller at higher frequencies. However,
I'm not holding gain constant, but size.
If the two antennas are the same
The increase in gain of a fixed length wire antenna is given in the ARRL
handbook and is less than monotonic with increasing frequency, further it
comes at a high price for a broadcast antenna: the main lobe veers away from
an optimal toroidal pattern and begins to align with the wire.
But I am
-Original Message-
From: Jim Eichner [mailto:jim.eich...@xantrex.com]
Sent: Wednesday, September 18, 2002 1:36 PM
To: 'Ken Javor'; Jim Eichner; 'EMC-PSTC - forum'
Subject: RE: Current from Car 12V cigarette lighter socket
Thanks.
The solution you propose is in the works. The SAE is
An antenna of some physical size will indeed have gain increasing with
frequency. There is some justification, a 1 GHz antenna being reasonably
small, for assuming that antennas will have similar sizes -- and increasing
gain -- above 960 MHz. However, I suspect that the original limit was
simply
When confronted by confused designers, I explain the USB feature I call the
common-mode noise detector. USB detects a new device connection via a very
simple non-differential circuit, even though the communication is otherwise
differential.
This problem was made noticable by the insistance
Following this thread, I looked up the FCC limits and see they are flat
above 960 MHz. I have a question for the forum. Given that a broadcast
type omni-directional antenna factor increases monotonically with increasing
frequency, why is the limit flat? The only way I could justify a flat
Eichner informed me that indeed, I have been scooped by the SAE and this in
the works.
--
From: John Woodgate j...@jmwa.demon.co.uk
To: emc-p...@majordomo.ieee.org
Subject: Re: Current from Car 12V cigarette lighter socket
Date: Wed, Sep 18, 2002, 4:33 PM
I read in !emc-pstc that Ken
Alan,
Level 1: (1V/M)Low-level electromagnetic radiation environment.
Levels typical of local radio/television stations located at more than 1
km, and transmitters/receivers of low power.
Level 2: (3V/M)Moderate electromagnetic radiation environment. Low
power portable transceivers
I read in !emc-pstc that dave.osb...@philips.com wrote (in
of6ce386fe.d271bb0a-on86256c38.0070a...@diamond.philips.com) about
'Medical equipment and EN61000-3-2' on Wed, 18 Sep 2002:
Hospitals, just like large office buildings are rarely directly connected to
the
public low-voltage
Alan,
Level 1: (1V/M)Low-level electromagnetic radiation environment.
Levels typical of local radio/television stations located at more than 1
km, and transmitters/receivers of low power.
Level 2: (3V/M)Moderate electromagnetic radiation environment. Low
power portable transceivers
I'm not an authority, but I would think that this is against both the
fire code and common sense. If an emergency developed such as electric
shock or fire and the breaker could not be manually opened, i see it as
tantamount to the locking of fire escape doors and many liability
concerns.
Many line filters do indeed have a bleeder resistor built in. There
are a few which do not, and I am familiar with one Delta filter that
does not. We added the bleeder across the terminals of the filter and
it was approved by UL. It just has to be done in accordance with
accepted
Neil,
Section 15.33 of FCC Part 15 Frequency Range of Radiated Measurements
provides you with this information.
Regards
Joe Martin
Applied Biosystems
I am getting multiple postings, even I think into the next day.
---
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
There has been some good responses to this post. And it is, in general,
true
that a manufacturer is not mandated, by law, to have the product LISTED
by an appropriate Safety Testing Agency (NRTL). However, it may be
required by the local inspection agency prior to installation. (This was
Hi Tom:
So, for voltage up to 450V d.c. (i.e. up to 318V a.c.), capacitor
up to 0.1uF will become a Limited Current Circuit, hence the voltage
is not Hazardous Voltage (1.2.8.4) - no additional condition would
be required for the capacitor connected to the primary circuit.
Greetings,
The Applied Biosystems Division located in the Houston Texas area has the
following opening in the Compliance Engineering Department:
Duties include leading EMC and product safety engineering functions,
including working with manufacturing and RD to determine requirements for
Another interesting point that can be made is I didn't say it was law, I
said List it or I won't buy it. Depending on the product (basically, if
there's a Listed competitor product on the market), you can make it happen.
In the US, often a Listing mark is enforced by marketing more than law.
The Darnell Group is a market research/publishing/advertising entity that has
been tracking the automotive industry changeover from 12V to 42V, as well as
other power supply issues.
They were offering a free web-newsletter called the power-pulse (or something
like that). I subscribed to
Hi Rob:
I am in discussions with a potential supplier of IT equipment, Its our
usual policy to request testing to a listed standard
such as UL 60950 for safety in North America.
The supplier has replied that this is not mandatory.
Is he correct? what compels safety
I read in !emc-pstc that Tyra, John john_t...@bose.com wrote (in
418fbd441c22d5118d860003470d43160543e...@cupid.bose.com) about
'EN60065 mains switches' on Thu, 19 Sep 2002:
Here is another issue where you will get conflicting opinions but I believe
that just because it is notified in the OJ does
I read in !emc-pstc that Tyra, John john_t...@bose.com wrote (in
418fbd441c22d5118d860003470d43160543e...@cupid.bose.com) about 'CE
Marking for Passive speakers' on Thu, 19 Sep 2002:
John, the added cost in our case is the fact that we include a copy of the
DoC with every product. Not required I
Hi John,
Even theory has to comply with practice, so i took my soldering iron...
I have to admit that modern capacitors do keep their charge too
long. I did some test with newer Y and X caps of 0.1 uF and they keep their
charge way too long - over 1 minute - without notable loss of
voltage (
Here is a very good discussion of the leagalities.
http://www.conformity.com/A02F18.pdf
Richard Woods
Sensormatic Electronics
Tyco International
-Original Message-
From: Gary McInturff [mailto:gary.mcintu...@worldwidepackets.com]
Sent: Thursday, September 19, 2002 12:40 PM
To:
Hi Warren,
As I understand the FCC Part 15 regs there are NO immunity requirements.
Indeed the FCC have in the past allowed the market to dictate the quality
of the EM design. Has there been a change??
Best Regards
Charles Grasso
Senior Compliance Engineer
Echostar Communications Corp.
Tel:
Hi
It is my understanding that the USB guidelines provide for EMI filtering
at the output. That is to say: for USB1 - ferrite beads and caps, for USBII
a common mode choke is recommended. Take a look in there.
Also, USB is a differential signal so appropriate design on the board needs
to be
Gert
Thanks for that investigation that I have not had the time for recently!
Now, maybe, the standards writing committees will begin to take this issue
on board and do something about it as the problem is generally technically
trivial to solve - the major issue then being to ensure that the
Well that's the $1M question, isn't it!
My involvement is tangential at best, but my understanding is that the
effort is not going to be coordinated as a grand simultaneous roll-out.
Rather each mfr of cars, trucks, boats, etc, will get around to it based on
their own needs. The drivers for
In a message dated 9/19/2002, Matt Aschenberg writes:
Our engineering team is looking for a spec that defines U.S pulse dialing.
Any suggestions?
Hi Matt:
As you may know, there are no regulatory requirements for pulse dialing in
FCC part 68. This means that any requirements you apply
You can't do much filtering on the USB lines due to signal integrity. We
have achieved good results with careful attention to PCB layout (an adequete
ground plane, don't even try 2-layer) and shielding, especially with the
cable.
Darrell Locke
Advanced Input Devices
-Original Message-
The Canadians accept FCC data, which DOES include immunity
requirements. There are no testing standards for immunity, only that
the device must accept any interference for normal operation. See the
labeling requirements for verification and certification in Part 15.
Warren Birmingham
Some states (e.g., North Carolina), counties (e.g., Orange, CA) and cities
(e.g., Los Angeles and San Francisco)have a legal requirement that all
electrical products for sale must be Listed. Some local electrical codes
(e.g., Oregon) require electrical equipment be Listed. Since my company
sells
Hi Dave:
I had the same question some time back, and came up with the following process.
1) For the resistive component, I applied a resistive load to the AC line, and
calculated R = dV/dI
2) For the inductive component, I measured the transient current through an 'X'
capacitor at the moment
Rob.
Required is an interesting term, and this is a long debate involving
OSHA, National Electrical Code, fire codes and when and if anybody inspects the
equipment before its installed.
There are places that you probably would be alright, some that you
wouldn't probably be
(the unplugging process may need to be repeated a few times until the
capacitor is disconnected when the mains is high at the time of
disconnection and so gets a decent charge!)
At a former employer, we monitored the wave form with a 'scope, and
repeatedly opened and closed the connection to
Here is another issue where you will get conflicting opinions but I believe
that just because it is notified in the OJ does not mean every country
will adopt it at the same time. You need to be careful as there are some
countries still working with the 5th edition so if you have a CB certificate
In a message dated 9/19/2002, you write:
So far, I've taken a large resistive load and measured the voltage drop on
the AC line. From that I calculated the total impedance of the AC line.
However, as you may suspect, with a resistive load, the power factor is
1.0.
So I can't vectorly,
Amund,
Like the US, Canada has just radiated and conducted emissions
requirements. The pertinent standard for Digital Apparatus is Industry
Canada's ICES-003 Issue 3, dated November 22, 1997. This standard may
be downloaded from:
http://strategis.ic.gc.ca/SSG/1/sf00020e.html
and the
I wish to thank everyone for taking the time to consider my questions. There
were a many good points brought up and it gave me some new issues to
consider, i.e. immunity testing for intense. As I expected the opinion was
split and I have to admit that I am still not convinced that CE Marking is
The Canadians accept FCC data, which DOES include immunity
requirements. There are no testing standards for immunity, only that
the device must accept any interference for normal operation. See the
labeling requirements for verification and certification in Part 15.
Warren Birmingham
I read in !emc-pstc that Spencer, David H david.spen...@usa.xerox.com
wrote (in 052106A55179D611B34300096BB02E3F8B1D@USAMCMS4) about
'Measuring AC Line Impedance' on Thu, 19 Sep 2002:
Is anyone familiar with a method to measure and calculate those values. The
generic values I have for short
I read in !emc-pstc that John Allen john.al...@era.co.uk wrote (in
BFE68AB0084CD311B4FB00508B014C8703CF9BEE@MERCURY) about 'Question:
Discharge capacitance 0.1 uF' on Thu, 19 Sep 2002:
Now, maybe, the standards writing committees will begin to take this issue
on board and do something about it
Patrick,
I don't know whether or not hospital power systems fall within the
scope of EN61000-3-2:2001. But in any case, compliance with EN61000-3-
2 is not required under the Medical Devices Directive.
The only harmonized EMC standard under the MDD is EN 60601-1-2:1993,
which does not have
Hello all,
I am certain there are more than a few telecom gurus on this list.
Maybe you can help me out.
Our engineering team is looking for a spec that defines U.S pulse dialing.
Any suggestions?
Thanks for your help,
Mat Aschenberg
---
This
John -
I respectfully disagree that the standards bodies need to do
anything. It is the designers that must be aware of the
advancements of technology (such as described by Gert) and
update their practices accordingly. [Low ESR / High Q caps
are a good thing.] While I have no doubt about the
No.
Richard Woods
Sensormatic Electronics
Tyco International
-Original Message-
From: am...@westin-emission.no [mailto:am...@westin-emission.no]
Sent: Thursday, September 19, 2002 8:22 AM
To: emc-p...@majordomo.ieee.org
Subject: EMC immunity requirements in Canada?
As far as I
Group,
I am in discussions with a potential supplier of IT equipment, Its our usual
policy to request testing to a listed standard
such as UL 60950 for safety in North America.
The supplier has replied that this is not mandatory.
Is he correct? what compels safety testing for IT equipment in
Hi Charles, Warren
Seems that a few of us know what DOES happen and the longterm results, but
quite a few others don't believe that it does - and that even it does then
it is not very important.
The difference between reality and theory!
I suggest that the non-believers try it for themselves
In a message dated 9/19/2002, you write:
So far, I've taken a large resistive load and measured the voltage drop on
the AC line. From that I calculated the total impedance of the AC line.
However, as you may suspect, with a resistive load, the power factor is
1.0.
So I can't vectorly,
Amund:
Industry Canada does not have immunity requirements for Class A/B products.
Regards
Kevin Keegan
KES Associates
Ottawa Canada
- Original Message -
From: am...@westin-emission.no
To: emc-p...@majordomo.ieee.org
Sent: Thursday, September 19, 2002 8:22 AM
Subject: EMC immunity
Be careful about using the antenna factor. The published antenna factor is
a receive antenna factor, and for what you are trying to do you need the
transmit antenna factor. You can calculate one from the other if you know
the frequency, but they are not identical. I can provide that
As far as I remember, US (FCC) do only have emission (radiated / conducted)
requirements.
What about Canada (IC) do they have immunity requirements in addition ?
Best regards
Amund Westin, Oslo/ NORWAY
---
This message is from the IEEE EMC Society
Using the antenna factor of a particular antenna, one can compute the
theoretical power required to create a specified E-field at a specified
distance. Without over specifying the power amplifier (assume Class A), what
minimum safety factor should be added to the theoretical values to account
for
I'm trying to characterize the 50Hz AC line impedance of my facility, for
comparison to the values specified in IEC61000-3-3. I've come across
generic short circuit values for the Resistive and Inductive components.
However, I need to determine exactly what these values are ideally through a
Gert
Thanks for that investigation that I have not had the time for recently!
Now, maybe, the standards writing committees will begin to take this issue
on board and do something about it as the problem is generally technically
trivial to solve - the major issue then being to ensure that the
I read in !emc-pstc that Colgan, Chris chris.col...@tagmclaren.com
wrote (in AE0F4BD08FEAD211895900805FE67B1F01425A8B@CAT) about 'EN60065
mains switches' on Thu, 19 Sep 2002:
I'm all for using the 7th edition but it is not mentioned in the LVD List of
Harmonised Standards yet. Any idea when it
I read in !emc-pstc that Gordon,Ian ian.gor...@edwards.boc.com wrote
(in E1BA0362B28ED211A1E80008C71EA306018190AE@EXC_EAS01) about 'CE
Marking for Passive speakers' on Thu, 19 Sep 2002:
By the wider issue I was referring to your assertion that The EMC
Guidelines document explains that having no
Hi John,
Even theory has to comply with practice, so i took my soldering iron...
I have to admit that modern capacitors do keep their charge too
long. I did some test with newer Y and X caps of 0.1 uF and they keep their
charge way too long - over 1 minute - without notable loss of
voltage (
I'm all for using the 7th edition but it is not mentioned in the LVD List of
Harmonised Standards yet. Any idea when it will be?
Cheers
Chris
-Original Message-
From: John Woodgate [SMTP:j...@jmwa.demon.co.uk]
Sent: Wednesday, September 18, 2002 9:47 PM
To:
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