Most people use the EM clamp. We test to EN50130-4 alarm system limits:
10V, pulsed and AM modulated. The test is trivial because of the inherent
immunity of Ethernet; be sure you understand the EUT and AE port
partitioning algorithms.
Constructing a CDN that compliant to ANSI/IEEE
Good People
I have not been able to find any requirements on the TUV or UL websites for
minimum size requirements of their respective logos (when used as a safety
mark on the recognized/certified product).
Could someone provide a pointer to (agency-published) guidance for logo
dims?
Thanks
Although this is not an EMC standard it is related. My lab has been asked to
test our products to the magnetic standards of IATA Packing Instruction 902.
This test determines the ability of a device to change a compass reading. I
have the regulations and know how to do the test, but do not do it
In the very specific case of Medical devices, the newest edition of IEC
60601-1-2 specifies -5 testing at the extreme ends the range of
continuously adaptive supply and in each range of a switched range supply.
Regards,
Brent DeWitt
gunter_j_ma...@embraco.com.br@majordomo.ieee.org on
Hello Group,
I have been tasked with obtaining A2LA accreditation for my internal (first
party) lab. We have about ten technicians, perform all standard suite of IEC
EMC tests along with vibration, shock, bump and environmental (cold, dry heat,
damp heat) testing.
I have attended ISO 17025
I am not advocating placing an inductor in series with the cap. Circulating
loop currents in the power and ground traces will create emissions, but
those currents can be reduced by use of bypass capacitors or an L-type
filter (capacitor and inductor) in the 5V trace. At least, according to
Although this is not an EMC standard it is related. My lab has been asked to
test our products to the magnetic standards of IATA Packing Instruction 902.
This test determines the ability of a device to change a compass reading. I
have the regulations and know how to do the test, but do not do it
List
I suppose that EN61000-4-4, 4-5 and 4-6 do not mention the input voltage to
be applied to the EUT during the tests.
For a product with a voltage range, like 198 up to 264Vac (230Vac nominal),
what should be the right value ?
Or do I need to look for the worst voltage case ?
Thank you for
Amund,
I have encountered similar problems with similarly designed boards. In one
interesting case, I was able to get 30 dB reduction in radiated EMI by
adding a series resistor to a (fairly short) low-frequency clock line. Due
to use of modern devices, its rise and fall times were less than a
Not sure this would be a cure in this instance. This is effectively the
same as adding a lossy inductor in series with the cap, which would tend
to negate any benefits of using a cap with lower self inductance.
Bob Wilson
TIR Systems Ltd.
Vancouver.
-Original Message-
From:
Years ago in ultrasonic echocardiography instrumentation (the ultrasonics
analog is a wide band receiver listening in the 1-10MHz region down to less
than 10uV, so the digital had better be quiet!) which used a bit slice
architecture system containing Schottky logic with a clock of 20MHz for
Jeffrey,
You are correct. The standards do not address the usage of multiple
antennas. We have not participated in any Round Robin testing multiple
antennas in the test chamber, so I am not exactly sure what the possible
effects would be in terms of getting accurate and/or repeatable results.
Hmmm.
I've read a couple of other replies on this...good suggestions. I have
also read your re-replies which suggest that you have a two layer
planeless board.
I understand that you are trying to get an unwanted 156Mhz off of the 5V
line. A couple of thoughts come to mind.
First 156Mhz
Consider adding a ferrite bead in the 5V trace to the microprocessor.
Richard Woods
Sensormatic Electronics
Tyco International
-Original Message-
From: am...@westin-emission.no [mailto:am...@westin-emission.no]
Sent: Wednesday, April 17, 2002 4:50 PM
To: emc-p...@majordomo.ieee.org
Interesting articles on your web-site, Tim.
BTW, how about just using a 100 pF capacitor with the 'leads' hugging close
to the microprocessor package
There's a mile from the Vcc pin to ground, that's another problem. No
ground plane, only ground traces which is routed around on the PCB. This
Amund,
In the absence of any layout information that can evaluate the loop
inductances, I suggest you read what I wrote about placing two capacitor in
parallel which can be found on Chapter 3 of my thesis. A link is available
in:
http://www.geocities.com/timfoo6143/index.html
BTW, how about
There will be a Northeast Product Safety Society meeting on Wednesday,
April 24, at EMC Corporation's Customer Briefing Center in Hopkinton,
MA. A social hour with light refreshments will begin at 7:00 PM and the
technical meeting will start at 7:30 PM. James Norton, CEO of EMD
Optima, will be
Correct, the picture is complex. The PCB is 2-layer with signal, 5V-power
and 0V-ref lines routed on both sides. There is no ground layer/plane. There
must be a large number of RF current loops because the 0V-lines are routed
up and down and around.
Beside trying to achieve a good decoupling I
I read in !emc-pstc that Robert Wilson robert_wil...@tirsys.com wrote
(in 3FF57405336C9B4C976A1819F860A2560F696F@xng_tirsys.TIRSYS.COM)
about 'Decoupling - capacitor values', on Wed, 17 Apr 2002:
The main
reason is that the ESR of the larger cap begins to rise to unacceptable
levels as frequency
Capacitors can continue to function quite well above their self
resonance. You should not be worrying about choosing a cap based on self
resonance per se.
However, it is standard practice to parallel a 0,1 uF bulk bypass cap
with a much smaller NP0 or C0G type (say 470 pF or 1 nF), especially
Yes, it makes sense. But the goal here is preventing or reducing Vcc drop
during the time the microprocessor is switching. You need not only low
reactance, but *also* enough capacitance to supply the current needed
_while it is switching_. You have not given enough information here to tell
if
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