of you would like a target to use
and to provide feedback. Who wants a target? Step right up and get your red
hot Pelligrini targets!
Dave Cuthbert
Micron Technology
From: Jim Ericson [mailto:jde...@nas.com]
Sent: Saturday, May 03, 2003 5:09 PM
To: emcpost
Cc: drcuthbert
Subject: Re: ESD Gun
Here is a PCB checklist at http://www.x
linx.com/xlnx/xil_prodcat_product.jsp?title=si_pcbcheck
Here is another link at xilinx: http://
ww.xilinx.com/xlnx/xil_prodcat_landingpage.jsp?title=Signal+Integrity
Dave Cuthbert
Micron Technology
This message is from the IEEE EMC Society Product
I will send a list of three good books on these two connected subjects (signal
integrity and PCB EMC) in a day or two. Basically and briefly here is my
viewpoint:
For signal integrity you must be familiar with transmission lines; how to
visualize signal propagation along a T-line and how to
I sometimes use a small piece of Kapton tape to hold a thermocouple.
Dave Cuthbert
Micron Technology
From: John Allen [mailto:john.al...@era.co.uk]
Sent: Wednesday, April 23, 2003 10:29 AM
To: IEEE EMC/Product Safety (IEEE, EMC/Product Safety)
Subject: RE: Thermocouple glue
Hi
Is the discharge requirement so that the unit cannot power up (burn up in
shipping)? I have purchased a couple of items that had plastic tape inserted
between the battery contacts and the battery connector. Is this acceptable?
Dave Cuthbert
Micron Technology
From: don_borow...@selinc.com
to clean the gold
contacts.
Dave Cuthbert
From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Monday, April 21, 2003 5:20 PM
To: drcuthbert; 'djumbdenst...@tycoint.com'; emc-p...@majordomo.ieee.org
Subject: Re: Low signal switching
I can certainly suggest a solution, although it would take
Don,
I have encountered this problem with low-level signals. It seems to vary
greatly from manufacturer to manufacturer (the company we had the best results
with went out of business). When the contact(s) became dirty I would run a DC
current and clean it. The problem would quickly return and
George,
path loss is independent of frequency. The reason frequency appears in this
formula is that path loss is the loss between two dipole antennas. The
capture area of a dipole (about 1/8 sq wavelength) drops by a factor of 4 with
each doubling of frequency (20LOGF/f). Anyway, the standard
Good points. Perhaps the units to be tested need to be given a simulated
shipping ordeal prior to testing. Dropping, shaking, heating, and cooling.
Dave Cuthbert
From: Gary McInturff [mailto:gary.mcintu...@worldwidepackets.com]
Sent: Wednesday, March 26, 2003 8:35 AM
To: lfresea...@aol.com;
Tim,
what is CEM?
Dave Cuthbert
From: Wan Juang Foo [mailto:f...@np.edu.sg]
Sent: Thursday, March 27, 2003 2:34 AM
To: drcuthbert; emc-p...@majordomo.ieee.org
Subject: Re: NEC-2 simulations
I use NEC-2 in a limited way.
Good to hear that there are others on the PSTC list that does
Charlie,
1/2 lambda is 7.5 cm at 2 GHz. At this distance the field strength is 67 V/m
assuming far field. So, no near field calculations are needed as long as the
distance is greater than approximately 10 cm. The actual field is not that
difficult to calculate anyway. Or, just use NEC to simulate
What would NARTE say about certified EMC engineers and technicians signing off
on equipment that does not make the grade? It would be great if everyone and
every company handled the issue of EMC ethically. But since the world does not
always work this way...I favor the idea of a fine for every
Is a semi-anechoic chamber really needed? Testing close-in inside of a
building should work, I would think.
Dave Cuthbert
Micron Technology
From: Hjálmar Árnason [mailto:hjal...@mi.is]
Sent: Thursday, March 27, 2003 4:14 PM
To: emc-p...@majordomo.ieee.org
Subject: Calibrating police
: robert Macy [mailto:m...@california.com]
Sent: Wednesday, March 26, 2003 6:02 PM
To: drcuthbert; 'emc-p...@majordomo.ieee.org'
Subject: Re: high immunity
If GW, wouldn't that voltage be more like 600KV/m, or at
least 30KV/m?
- Robert -
Robert A. Macy, PEm...@california.com
Derrick,
I'm sure you used the antenna factors correctly but I'll put in my 2 cents
worth anyway. Were the AF's used correctly? You need the TX AF and the RX AF.
If the receive antenna factor was used as the transmit antenna factor that
will skew the calibration.
Dave Cuthbert
This message
With the advent of E-weapons we might need some new immunity specs. I read
that they can output several GW. Testing for equipment survival at over 5000
V/m should be fun (and profitable to some).
Dave Cuthbert
Micron Technology
This message is from the IEEE EMC Society Product Safety
Derek,
most interesting data. I have two questions: What software are you exercising
the PC's with and is the spread spectrum enabled? I assume you are using an
RBW of 120 kHz and using Quasi-peak detection.
In my limited experience I have found that the software that is exercising the
PC can
I have been using NEC-2 antenna software for simulations of EMC situations.
Antenna-to-antenna, ferrites on cables, DUT cables, BC station field strength,
and such. Anyone else using NEC for this?
Dave Cuthbert
Micron Technology
This message is from the IEEE EMC Society Product
To: drcuthbert; emc-p...@majordomo.ieee.org
Subject: Re: surge Z?
Dave,
Section 6.1 of EN 61000-4-5:1995 says the generator has an effective
output impedance of 2 ohms.
John Barnes KS4GL, PE, NCE, ESDC Eng., SM IEEE
dBi Corporation
http
Anyone know the source impedance used for EN 61000-4-5 Surge testing?
Dave Cuthbert
Micron Technology
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
Aaron,
I believe you use the standard receiver RBW and use the peak hold mode.
Depending on how the spread spectrum operates (I.E. wideband noise, or
frequency hopping, etc.) the receiver and the transmitter will eventually line
up.
Dave Cuthbert
From: Price, Ed [mailto:ed.pr...@cubic.com]
We are currently going through a similar process with a board designed for
in-house use. We are planning to go for CE certification. We designed it to
EN61010 and it passed our own safety testing and radiated/immunity and ESD.
But it seems to be a gray area as to having it certified or not. I
Why not blast the DUT with 10V/m at all frequencies? If it misbehaves in the
3V/m bands then 3V/m could be tried. If you want some high E-field try my
house (or another ham's house). I often run fields to the FCC safety limit in
my house. When operating 160 meters I can light a 40 watt
Here is a link to my latest EDN Design Idea article (Transmission line tests
1-kW device using only 100W): http://ww
.e-insite.net/ednmag/index.asp?layout=a
ticlestt=000articleid=CA276211pubdate=2%2F20%2F2003spacedesc=designideas
Dave Cuthbert
Micron Technology
This
The fact that going from unshielded to shielded cable cut emissions by 6 dB
does not necessarily mean that the shield cut cable emissions by only 6 dB. It
could mean that the cable emissions have been greatly reduced but another part
of the system has emissions that are 6 dB below the original
Maybe he had a special low EMI cell phone? But seriously, a useful product
would be a cell phone detector with an audible alarm, or a silent alarm to
alert security.
Dave Cuthbert
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: Saturday, February 22, 2003 1:05 AM
To:
I completely agree with Ken Javor. Solid theory and solid conclusions.
Dave Cuthbert
From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Thursday, February 20, 2003 4:53 PM
To: pwell...@csw.l-3com.com; 72146@compuserve.com; emc-p...@ieee.org
Subject: Re: RE02 cabling problem
Richard,
is the proposed increase to support magnetic field signaling, such as in
automobiles?
Dave Cuthbert
From: richwo...@tycoint.com [mailto:richwo...@tycoint.com]
Sent: Friday, February 21, 2003 6:30 AM
To: emc-p...@majordomo.ieee.org
Subject: Japan 13.56 MHz
Last year a Japan was
Muriel,
interesting question. Considering common mode noise on the load wires: With
the load at the end of the wires, but not grounded, you have a monopole
antenna. With the load wires terminated into a filter (I'm assuming low-Z to
GND) you have a loop antenna. I ran a quick simulation using
I should emphasize that this applies to equipment build by company A for use
by company A only. A label on the equipment stating this is probably a good
idea.
Dave Cuthbert
From: drcuthbert [mailto:drcuthb...@micron.com]
Sent: Wednesday, February 19, 2003 3:28 PM
To: 'Joe P Martin'; emc-p
Rick,
I like to use a clamp-on DC current probe and an oscilloscope. Tektronix
makes these probes. If the 'scope has an RMS feature it will calculate the
RMS current over the length of the trace. In this way you can adjust the
length of the RMS operation. If your 'scope does not have this feature
Kurt,
this could be aviation communications. AM voice is centered at about 121
MHz.
Dave
From: Kurt Fischer [mailto:kurt.fisc...@hyperinterop.com]
Sent: Tuesday, February 11, 2003 8:03 AM
To: emc-p...@majordomo.ieee.org
Subject: Real product interference source at 121 MHz
Hello all,
A
Kim,
Screw/Washer choice:
- should a washer be used or not? ONE COMPANY I WORKED FOR USED SCREWS WITH
INTEGRAL STAR WASHERS. WE NEVER HAD ONE WORK LOOSE EVEN IN MOBILE
APPLICATIONS.
- Is an adhesive like Loctite a reasonable alternative to lock washers in
this case? I WOULD THINK LOCKTITE WOULD
An interesting article in the January issue of EMC Compliance Journal
EMC-Related Functional Safety
http://www.compliance-club.com/article.php?sid=119mode=order=0
Dave Cuthbert
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Simply terminating the shield at the screened room wall eliminates common
mode shield current. No more filtering needs to be done.
Dave Cuthbert
Micron Technology
From: Luke Turnbull [mailto:luke.turnb...@trw.com]
Sent: Monday, February 10, 2003 7:38 AM
To:
Subject: GPIB filtered
Ed,
I use Vicor for power in this range. We have had good reliability in a lab
setting. The documentation could be better but we are used to Vicor and just
keep using them.
Dave Cuthbert
From: Price, Ed [mailto:ed.pr...@cubic.com]
Sent: Tuesday, February 04, 2003 4:10 PM
To: 'EMC-PSTC List'
Message-
From: Chris Maxwell
Sent: Tuesday, February 04, 2003 5:32 AM
Exactly!
Chris Maxwell
-Original Message-
From: drcuthbert [SMTP:drcuthb...@micron.com]
Sent: Monday, February 03, 2003 7:50 PM
What is needed is the I squared t rating of the
breaker
, Conformity, or Printed Circuit design magazine.
Dave Cuthbert
Micron Technology
From: Chris Maxwell [mailto:chris.maxw...@nettest.com]
Sent: Tuesday, February 04, 2003 6:32 AM
To: drcuthbert; John Woodgate; emc-p...@majordomo.ieee.org
Subject: RE: EN60950 protective conductor test
What is needed is the I squared t rating of the breaker. Then the (I^2)(t)
rating of the PCB. Then you know if the PCB can take it.
Dave Cuthbert
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: Monday, February 03, 2003 4:15 PM
To: emc-p...@majordomo.ieee.org
Subject: EN60950
I worked on a 1 MW, 160 GHz Gyrotron in 1982 that used a diamond waveguide
window. Yes diamond is the up-and-coming power electronics material with 50X
the thermal conductivity of copper. It is also starting to be used as a
protective thinfilm material.
Dave Cuthbert
From: Fred Townsend
that drcuthbert drcuthb...@micron.com wrote (in
cfefa50c9bcad21197470001fa7eba6b14121...@ntexchange05.micron.com)
about 'EN55022:1998 + A1:2000' on Wed, 29 Jan 2003:
And I have used an MFJ-259B (only
$260) to measure ferrites from 1.7 to 170 MHz.
What is an MFJ-259B and where can I buy one
How can a ferrite clamp be called a CMAD Common Mode Absorption Device? It
reduces EM radiation
by reducing the current through the antenna, not by absorbing RF. It
could, however, be called a CMAD Common Mode Attenuation Device.
Dave Cuthbert
From: John Woodgate
See the May 2002 issue
From: drcuthbert [mailto:drcuthb...@micron.com]
Sent: Friday, January 31, 2003 6:55 AM
To: emc-p...@ieee.org
Subject: Helmholtz article
Here is the link to the Conformity magazine article: Magnetic Field
Calibration: Unwinding The Helmholtz Coil, by Isidor Straus
http
Here is the link to the Conformity magazine article: Magnetic Field
Calibration: Unwinding The Helmholtz Coil, by Isidor Straus
http://www.conformity.com/featurearticlesarchive.html#June%202002
I used the formulas in this article to design and build an active ELF loop
antenna.
Dave
Brian,
I believe that forcing a FET failure would be a good test but should be in
addition to the mechanical short method. If your power supply is safe for both
failure modes that would be great. The fuse should open before the failed FET
can cause a heat or fire problem. And it was already a
Chris' Maxwell equations look correct. But the point at which ferrites are
placed will not always have a common mode impedance of 50 ohms. Here's An
example: a large DUT has a 1 meter long cable that connects to the ground
plane. At 75 MHz the common mode impedance of the cable, at the DUT, is
The EM radiation from wires with and without ferrite cores can be simulated
with NEC. The required parameters are: length of wire, physical orientation,
how the end is terminated (floating? To ground?, frequency, the RL model of
the ferrite). Then one can move the ferrite around to see what
I don't have a copy of EN55022 to look at so I'll ask a question: How many
ferrite clamps and what type are specified? And are they placed at various
places, at one location only, or placed as with a Bicon balun?
Dave Cuthbert
Micron Technology
From: richwo...@tycoint.com
But in the end it doesn't matter, does it? A dB is a dB. An increase in SPL
of 6 dB is the same as an increase in sound power of 6 dB. Just like a 6dB
change in voltage results in a 6dB change in power. Wonderful things, those
dB's..
Dave Cuthbert
Micron Technology
From: drcuthbert
Gordon,
the May 2002 issue of Conformity magazine had an excellent article on
Helmholtz coils. I checked their website but didn't see how to access old
issues. If you can't get a copy online I will be glad to FAX you a copy of
the article. To put things in perspective we can think about the
The resistance is about 20 ohms, and not 10 ohms. Now you needed 400 volts
to obtain 20 amps through the two coils in series. Or, run them in parallel
with 200 volts. This might be off a bit but I get 5 mN for the force between
the two coils. So, they aren't going to tear the setup apart. Almost
This probably comes under the heading of due diligence.
Dave Cuthbert
Kris,
In my reading of the standard, and the next modification will include
that clearly, you need to test discharges to the shell of the USB
connector, as there will not be a connector in there all the time.
There is
Quite right for uncorrelated noise.
To add to this discussing we can think about the response of the human ear
to sound
level. A 3 dB increase in SPL does not sound twice as loud. If I
remember correctly it takes a 6-8 dB increase to sound twice as loud. So
is the
goal to meet a standard or
I 'm afraid that my response to Neven's comments concerning EFT might have
sounded like I didn't approve of his method. Far from it, I think his method
is sound. I added my comments about component value selection as an aside.
Keep up the good work.
Dave Cuthbert
Micron Technology
Amund,
Several EU standards have been harmonized with the United States UL
standards. A list can be found at
http://ulstandardsinfonet.ul.com/catalog/stdscatframe.html
For example, UL 60950 the same as EN 60950. So, I'm thinking that if your
device meets EU safety requirements it will make it
On the subject of adding caps in circuits for noise immunity. Rather than
just throwing in a value of 0.1 uF, finding it works, and calling it good I
like to use a different approach. Determine the lowest value that will fix
the immunity problem. Then find the largest value that will still allow
I assume this is an off line switcher. If so, the FET is at mains potential
and the required creepage and clearance distances is the same as the
hot-to-ground creepage requirement(4 mm or is it 3 mm? for creepage).
I would not use the chassis as a heatsink myself. Even dirt cheap PC power
Does this apply to in-house test equipment? That is, equipment that is built
in-house and remains on site? In the past I have designed in-house equipment
to meet the safety standards but did not send the equipment out for testing
and certification.
Dave
From: Gregg Kervill
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: Saturday, January 11, 2003 5:33 AM
To: emc-p...@majordomo.ieee.org
Subject: Re: Fiber optic cable testing per EN 55022:1998 ?
I read in !emc-pstc that drcuthbert drcuthb...@micron.com wrote (in
cfefa50c9bcad21197470001fa7eba6b14121
I don't think an EM wave is affected by another magnetic or electric field.
There is no mixing in a vacuum (and CFA antennas don't exist). And I guess
you are correct on charge creating an EM wave. A positive hydrogen atom
would work (I think) and it has no electron. Acceleration of charge is
Chris,
some excellent points! My take on this is that a fiber optical cable has a
cutoff frequency that is way above the RF frequencies we are concerned
with. It just won't act as a waveguide for what we consider RF wavelengths.
However, I think the optical cable certainly does leak a bit at
Bob,
here is a website with good info on this subject:
http://www.ita.doc.gov/td/machinery/ecabroad/
This link came from this site
http://users.metro2000.net/~purwinc/seec2_2.htm
which has some more links.
Dave Cuthbert
Micron Technology Signal Integrity group
From: rehel...@mmm.com
Steve,
can you provide more details such as:
The type of fluid and the conductivity
The physical relationship between your equipment and the application?
How is the fluid piped?
The RF frequency?
What is the symptom that you observe?
Here is my first thought assuming that the chiller pipes the
For those of you who subscribe to Applied Microwaves and Wireless magazine,
they ceased publication in September. And another long time magazine has
gone belly up. Poptronics (a combination of the two magazines; Popular
Electronics and Electronics Now), a very old hobby magazine, is gone.
Peter,
I would begin by reviewing the construction of CE-marked portable tool
battery packs. Things such as UL-94V material, fuses, wiring, and so on.
Then see how this applies to the soft enclosure you are contemplating. I
would be concerned about what happens when the pack/cells are damaged
Sam,
concerning the 60 volts of bleed-over: I'm assuming the 230 volt outputs of
the 1:2 transformer are floating and the 60 volts was measured between one
transformer output line and PE GND using a DMM (10 M ohm input). If this is
so, this indicates a primary-to-secondary capacitance of a few
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