Most of the stories are stories about EMC fixes.
I've got one that is not and won't be fixed. I
just live with it!
It involves my '96 Honda Accord, bought new.
I'm in San Diego, about 100 miles south of Los
Angeles. I noticed that 50 kW Los Angeles AM
stations such as KFI and KNX were
Jeff,
It's a bit difficult to provide an exact answer since it's dependent on the
design of your system. Is the system approved by an NRTL? What is the
nature of the approval (i.e. listed, recognized, field investigated, etc.).
Different AHJ's may interpret and accept different markings from
Dear All Safety Engineers/Technicians,
I would like to make a survey of what test equipment (multimeter,
scope, etc.) you or your friendly test house use to measure the
voltage during the leakage current measurements in UL1950/EN 60
950.
WE USE:
OUR THIRD PARTY TEST HOUSE USES:
PETER S.
Ed, now THAT is a good one. it should win.
It's not that unusual though. It happens quite often just like you said,
specially the part about the VP getting promoted. The tester gets blamed if
the room fails. They dont want you to find leaks, they want you to do
something and then write a report
February 1999:
There we were sitting in the delivery room waiting for the baby to come
The TV is on in the room (to distract the wife in between contractions...it
didn't work but that's a different story). Attached to my wife is an automated
rather new and high tech looking blood pressure
Allen,
You are right. Transparent solids have much less loss for light waves than
opaque. And mirror-like solids reflect most of light waves.
B Ma
-
Original Text
From: Allen Tudor allen_tu...@pairgain.com, on 3/11/99 1:21 PM:
This question sounds goofy, but here goes anyway
Jeff Hi!
Most probably your rack system is operating in an industrial
environment. Power Supplies used in such environments must
either be Listed to UL508 or if Recognized (to UL1950 for example)
can be accepted if loaded to 50% of its rating.
I am not sure where in the NEC you can find this
Ed, if there is a grand prize to be awarded here for the most amusing
account ... you've got it hands down with this one... and your closing
statement, is a gem !
george
-Original Message-
From: ed.pr...@cubic.com [SMTP:ed.pr...@cubic.com]
Sent: Thursday, March 11, 1999 11:59 AM
To:
I would recommend that Doug Smith of Auspex Systems
answer this one as he has presented this at an ANSI C63
ESD meeting and to the FAA.(He managed to crash their
computers)!!
Thank you
Charles Grasso
Advisory Engineer
StorageTek
2270Sth 88th Street
Louisville CO 80027 M/S 4247.
Tel:303-673-2908
Hans,
IIf we're speaking about ITE, your product must meet IS1121 which
is harmonized fully with IEC 950 A4 (except for Israel deviations;
israeli plug, safety instructions and markings in Hebrew and RFI -
radiated emissions only). You are required by law to meet these
requirements; however,
Richard,
Adding Approved disks, tapes and similar devices and adding
model designation usually involves paperwork. However,
adding/changing Approved , datacom and other similar equipment
usually requires a repeat of some of the tests, including but not
limited to Input, Leakage and
Well . . . from what I read so far . . .I think Ed's experience ranks right
'up there'! (Pun intended!) Seriously though . . . I think we've got a
winner
there!
John A. Juhasz
Product Qualification
Compliance Engr.
Fiber Options, Inc.
80 Orville Dr. Suite 102
Bohemia, NY 11716 USA
Tel:
Hello members!
Well, as long as we are all trading emc horror stories I might as
well pitch in. I have a pretty good one.
Just before the launch of Apollo 11 [the first manned moon landing]
NASA discovered a big emc problem: something was causing the fuel cells of
the command
Jeff, if your rack assembly including the power supply is Listed, then the
inspector has no authority to investigate the components included in that
Listed assembly. On the other hand, if you added a power supply to a Listed
rack, then that power supply must be Listed.
--
While not quite as bad as the disaster Ed Price described, I once had to fix
a shielded room built to the specifications of a self-described RF
expert. This gentleman had convinced his management that he could build a
cheap and easy facility. The intended site was an unused loft on the fourth
In one of my past lives, there was a safety inspector (agency not divulged
here) that adamantly defended his interpretation of the 94V marking on PWBs as
a voltage rating of the PWB. He even wrote us up for this for not having a
high
enough voltage rating. This guy, too, is still in the
This question sounds goofy, but here goes anyway
Why doesn't visible light travel through solid objects (plastic, wood, etc)?
Unless I've totally missed the boat, visible light is electromagnetic energy
beginning at about 100,000GHz. So why doesn't it behave like electromagnetic
energy
There is an expanation for this seemingly unlikely event.
Having coins in a baggie and jingeling them causes the following
events to occur:
The rubbing of a coin against the polymer causes triboelectric
charging of both the coin and localized areas of the bag. Since there
are multiple coins,
To whom it may concern,
Sorry, rather lengthy. I tried to cut it down.
I've finally realized I don't think I fully understand
European approvals and I'll discuss why with two examples.
The first example will go from the *system level* down
to the *sub-system level*. The second example
Hello Group,
Has anyone heard of a requirement in the National Electrical Code that power
supplies which are components of larger systems be approved by an NRTL? I
have an inspector telling me this, but our copy of the NEC is 20 years old,
and I can't find it, anyway. In this case, the power
Subject: Awards for Worst EMC/PS qualities
Author: b...@namg.us.anritsu.com (Bailin Ma) at Internet
Date:03/08/1999 8:03 AM
Hi Group,
We have already seen awards for the most misleading ads, worst attire,
worst films, .
Why not awards for worst EMC and PS qualities?
Barry Ma
Hi Philip,
Wish I could be at that meeting.
In my stead, please say my greetings to Grant, and ask him how is his
stickball game these days?
Mike Harris
Teccom Co.
tecco...@i-cafe.net
707-258-1360/fax 1361
--
From: Ling, Philip pl...@newport.com
To: emc-p...@ieee.org
Subject:
I once had a Safety Engineer tell me that a class 2 transformer had opened
during the overload test. He was measuring resistance primary to secondary
(Duh!!!). This guy is still in the Safety Field but they don't work here
thank God!!!
Monty Griffith
Senior Product Safety Engineer
EMC Quality
EMC Group:
The comments I received indicate the 85878A report generator software is
worth its salt and very useful for H.P.8591 series analyzers. There are some
software anomalies but H.P. customer support can quide one through the pitfalls.
Does anyone out there have an original 85878A software
In the early 1980's, I worked for a company that manufactured PCs and
peripherals. I worked in a Functional Testing Lab where we ran functional tests
on our new designs before allowing them to go to production.
I was testing a dot matrix printer which our company purchased the electronics
and
Some years ago, I carted a prototype down to a Maryland area test lab
for an EMI scan. What I didn't realize was that the lab technician who
built the prototype crossed the power and earth lines to the power
supply, resulting in a hot chassis.
Well, as might be expected, there was some problem
That's what I love about this mailing list. I learn something new most every
day. Thanks Tania!
--
From: Grant, Tania (Tania) [SMTP:tgr...@lucent.com]
Sent: Wednesday, March 10, 1999 4:27 PM
To: 'EMC-PSTC - forum'; 'WOODS, RICHARD'
Subject: RE:
Some time ago, in a far-away land, I saw a product that was on the lab
bench for some initial functionality testing (1-st rev. of the device). A
radio was close by, plugged to the same power circuit. The test engineer
could not listen to the radio due to the interference with the noise coming
from
Along the same lines, the old VW Beatles would put out so much noise that
you could pick them up on your FM receiver a hundred yards down the road.
Daniel W. Mitchell
Product Safety Associate Engineer
EOS Corp.
--
From: Hans Mellberg[SMTP:emcconsult...@yahoo.com]
Sent: Wednesday,
Hi Douglas,
What you described is very interesting! But I cannot understand Jingling
change in a ziplock bag produces very high levels of super fast transients
up into the GHz range. It seems to me that jingling coins, jangling keys,
and slamming metal door would certainly produce acoustic
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